The Geopolitics of the United States, Part 1: The Inevitable Empire
Editor's Note: Originally published Aug. 24, 2011, in two parts, Stratfor's U.S. monograph has proven one of our most popular analyses. We feature it today in honor of the Fourth of July holiday. It is the 16th in a series of monographs on the geopolitics of countries influential in world affairs. Click here for part two.
Like nearly all of the peoples of North and South America, most Americans are not originally from the territory that became the United States. They are a diverse collection of peoples primarily from a dozen different Western European states, mixed in with smaller groups from a hundred more. All of the New World entities struggled to carve a modern nation and state out of the American continents. Brazil is an excellent case of how that struggle can be a difficult one. The United States falls on the opposite end of the spectrum.
The American geography is an impressive one. The Greater Mississippi Basin together with the Intracoastal Waterway has more kilometers of navigable internal waterways than the rest of the world combined. The American Midwest is both overlaid by this waterway and is the world's largest contiguous piece of farmland. The U.S. Atlantic Coast possesses more major ports than the rest of the Western Hemisphere combined. Two vast oceans insulated the United States from Asian and European powers, deserts separate the United States from Mexico to the south, while lakes and forests separate the population centers in Canada from those in the United States. The United States has capital, food surpluses and physical insulation in excess of every other country in the world by an exceedingly large margin. So like the Turks, the Americans are not important because of who they are, but because of where they live.
The North American Core
North America is a triangle-shaped continent centered in the temperate portions of the Northern Hemisphere. It is of sufficient size that its northern reaches are fully Arctic and its southern reaches are fully tropical. Predominant wind currents carry moisture from west to east across the continent.
Climatically, the continent consists of a series of wide north-south precipitation bands largely shaped by the landmass' longitudinal topography. The Rocky Mountains dominate the Western third of the northern and central parts of North America, generating a rain-shadow effect just east of the mountain range -- an area known colloquially as the Great Plains. Farther east of this semiarid region are the well-watered plains of the prairie provinces of Canada and the American Midwest. This zone comprises both the most productive and the largest contiguous acreage of arable land on the planet.
East of this premier arable zone lies a second mountain chain known as the Appalachians. While this chain is far lower and thinner than the Rockies, it still constitutes a notable barrier to movement and economic development. However, the lower elevation of the mountains combined with the wide coastal plain of the East Coast does not result in the rain-shadow effect of the Great Plains. Consequently, the coastal plain of the East Coast is well-watered throughout.
In the continent's northern and southern reaches this longitudinal pattern is not quite so clear-cut. North of the Great Lakes region lies the Canadian Shield, an area where repeated glaciation has scraped off most of the topsoil. That, combined with the area's colder climate, means that these lands are not nearly as productive as regions farther south or west and, as such, remain largely unpopulated to the modern day. In the south -- Mexico -- the North American landmass narrows drastically from more than 5,000 kilometers (about 3,100 miles) wide to, at most, 2,000 kilometers, and in most locations less than 1,000 kilometers. The Mexican extension also occurs in the Rocky Mountain/Great Plains longitudinal zone, generating a wide, dry, irregular uplift that lacks the agricultural promise of the Canadian prairie provinces or American Midwest.
The continent's final geographic piece is an isthmus of varying width, known as Central America, that is too wet and rugged to develop into anything more than a series of isolated city-states, much less a single country that would have an impact on continental affairs. Due to a series of swamps and mountains where the two American continents join, there still is no road network linking them, and the two Americas only indirectly affect each other's development.
The most distinctive and important feature of North America is the river network in the middle third of the continent. While its components are larger in both volume and length than most of the world's rivers, this is not what sets the network apart. Very few of its tributaries begin at high elevations, making vast tracts of these rivers easily navigable. In the case of the Mississippi, the head of navigation -- just north of Minneapolis -- is 3,000 kilometers inland.
The network consists of six distinct river systems: the Missouri, Arkansas, Red, Ohio, Tennessee and, of course, the Mississippi. The unified nature of this system greatly enhances the region's usefulness and potential economic and political power. First, shipping goods via water is an order of magnitude cheaper than shipping them via land. The specific ratio varies greatly based on technological era and local topography, but in the petroleum age in the United States, the cost of transport via water is roughly 10 to 30 times cheaper than overland. This simple fact makes countries with robust maritime transport options extremely capital-rich when compared to countries limited to land-only options. This factor is the primary reason why the major economic powers of the past half-millennia have been Japan, Germany, France, the United Kingdom and the United States.
Third, the river network's unity greatly eases the issue of political integration. All of the peoples of the basin are part of the same economic system, ensuring constant contact and common interests. Regional proclivities obviously still arise, but this is not Northern Europe, where a variety of separate river systems have given rise to multiple national identities.
It is worth briefly explaining why Stratfor fixates on navigable rivers as opposed to coastlines. First, navigable rivers by definition service twice the land area of a coastline (rivers have two banks, coasts only one). Second, rivers are not subject to tidal forces, greatly easing the construction and maintenance of supporting infrastructure. Third, storm surges often accompany oceanic storms, which force the evacuation of oceanic ports. None of this eliminates the usefulness of coastal ports, but in terms of the capacity to generate capital, coastal regions are a poor second compared to lands with navigable rivers.
Second, there are the Great Lakes. Unlike the Greater Mississippi Basin, the Great Lakes are not naturally navigable due to winter freezes and obstacles such as Niagara Falls. However, over the past 200 years extensive hydrological engineering has been completed -- mostly by Canada -- to allow for full navigation on the lakes. Since 1960, penetrating halfway through the continent, the Great Lakes have provided a secondary water transport system that has opened up even more lands for productive use and provided even greater capacity for North American capital generation. The benefits of this system are reaped mainly by the warmer lands of the United States rather than the colder lands of Canada, but since the Great Lakes constitute Canada's only maritime transport option for reaching the interior, most of the engineering was paid for by Canadians rather than Americans.
Thus, the Greater Mississippi Basin is the continent's core, and whoever controls that core not only is certain to dominate the East Coast and Great Lakes regions but will also have the agricultural, transport, trade and political unification capacity to be a world power -- even without having to interact with the rest of the global system.
There is, of course, more to North America than simply this core region and its immediate satellites. There are many secondary stretches of agricultural land as well -- those just north of the Greater Mississippi Basin in south-central Canada, the lands just north of Lake Erie and Lake Ontario, the Atlantic coastal plain that wraps around the southern terminus of the Appalachians, California's Central Valley, the coastal plain of the Pacific Northwest, the highlands of central Mexico and the Veracruz region.
But all of these regions combined are considerably smaller than the American Midwest and are not ideal, agriculturally, as the Midwest is. Because the Great Lakes are not naturally navigable, costly canals must be constructed. The prairie provinces of south-central Canada lack a river transport system altogether. California's Central Valley requires irrigation. The Mexican highlands are semiarid and lack any navigable rivers.
The rivers of the American Atlantic coastal plain -- flowing down the eastern side of the Appalachians -- are neither particularly long nor interconnected. This makes them much more like the rivers of Northern Europe in that their separation localizes economic existence and fosters distinct political identities, dividing the region rather than uniting it. The formation of such local -- as opposed to national -- identities in many ways contributed to the American Civil War.
But the benefits of these secondary regions are not distributed evenly. What is now Mexico lacks even a single navigable river of any size. Its agricultural zones are disconnected and it boasts few good natural ports. Mexico's north is too dry while its south is too wet -- and both are too mountainous -- to support major population centers or robust agricultural activities. Additionally, the terrain is just rugged enough -- making transport just expensive enough -- to make it difficult for the central government to enforce its writ. The result is the near lawlessness of the cartel lands in the north and the irregular spasms of secessionist activity in the south.
Canada's maritime transport zones are far superior to those of Mexico but pale in comparison to those of the United States. Its first, the Great Lakes, not only requires engineering but is shared with the United States. The second, the St. Lawrence Seaway, is a solid option (again with sufficient engineering), but it services a region too cold to develop many dense population centers. None of Canada boasts naturally navigable rivers, often making it more attractive for Canada's provinces -- in particular the prairie provinces and British Columbia -- to integrate with the United States, where transport is cheaper, the climate supports a larger population and markets are more readily accessible. Additionally, the Canadian Shield greatly limits development opportunities. This vast region -- which covers more than half of Canada's landmass and starkly separates Quebec City, Montreal, Toronto and the prairie provinces -- consists of a rocky, broken landscape perfect for canoeing and backpacking but unsuitable for agriculture or habitation.
So long as the United States has uninterrupted control of the continental core -- which itself enjoys independent and interconnected ocean access -- the specific locations of the country's northern and southern boundaries are somewhat immaterial to continental politics. To the south, the Chihuahuan and Sonoran deserts are a significant barrier in both directions, making the exceedingly shallow Rio Grande a logical -- but hardly absolute -- border line. The eastern end of the border could be anywhere within 300 kilometers north or south of its current location (at present the border region's southernmost ports -- Brownsville and Corpus Christi -- lie on the U.S. side of the border). As one moves westward to the barren lands of New Mexico, Arizona, Chihuahua and Sonora, the possible variance increases considerably. Even controlling the mouth of the Colorado River where it empties into the Gulf of California is not a critical issue, since hydroelectric development in the United States prevents the river from reaching the Gulf in most years, making it useless for transport.
In the north, the Great Lakes are obviously an ideal break point in the middle of the border region, but the specific location of the line along the rest of the border is largely irrelevant. East of the lakes, low mountains and thick forests dominate the landscape -- not the sort of terrain to generate a power that could challenge the U.S. East Coast. The border here could theoretically lie anywhere between the St. Lawrence Seaway and Massachusetts without compromising the American population centers on the East Coast (although, of course, the farther north the line is the more secure the East Coast will be). West of the lakes is flat prairie that can be easily crossed, but the land is too cold and often too dry, and, like the east, it cannot support a large population. So long as the border lies north of the bulk of the Missouri River's expansive watershed, the border's specific location is somewhat academic, and it becomes even more so when one reaches the Rockies.
On the far western end of the U.S.-Canada border is the only location where there could be some border friction. The entrance to Puget Sound -- one of the world's best natural harbors -- is commanded by Vancouver Island. Most of the former is United States territory, but the latter is Canadian -- in fact, the capital of British Columbia, Victoria, sits on the southern tip of that strategic island for precisely that reason. However, the fact that British Columbia is more than 3,000 kilometers from the Toronto region and that there is a 12:1 population imbalance between British Columbia and the American West Coast largely eliminates the possibility of Canadian territorial aggression.
It is common knowledge that the United States began as 13 rebellious colonies along the east coast of the center third of the North American continent. But the United States as an entity was not a sure thing in the beginning. France controlled the bulk of the useful territory that in time would enable the United States to rise to power, while the Spanish empire boasted a larger and more robust economy and population in the New World than the fledgling United States. Most of the original 13 colonies were lightly populated by European standards -- only Philadelphia could be considered a true city in the European sense -- and were linked by only the most basic of physical infrastructure. Additionally, rivers flowed west to east across the coastal plain, tending to sequester regional identities rather than unify them.
But the young United States held two advantages. First, without exception, all of the European empires saw their New World holdings as secondary concerns. For them, the real game -- and always the real war -- was on another continent in a different hemisphere. Europe's overseas colonies were either supplementary sources of income or chips to be traded away on the poker table of Europe. France did not even bother using its American territories to dispose of undesirable segments of its society, while Spain granted its viceroys wide latitude in how they governed imperial territories simply because it was not very important so long as the silver and gold shipments kept arriving. With European attentions diverted elsewhere, the young United States had an opportunity to carve out a future for itself relatively free of European entanglements.
Second, the early United States did not face any severe geographic challenges. The barrier island system and local rivers provided a number of options that allowed for rapid cultural and economic expansion up and down the East Coast. The coastal plain -- particularly in what would become the American South -- was sufficiently wide and well-watered to allow for the steady expansion of cities and farmland. Choices were limited, but so were challenges. This was not England, an island that forced the early state into the expense of a navy. This was not France, a country with three coasts and two land borders that forced Paris to constantly deal with threats from multiple directions. This was not Russia, a massive country suffering from short growing seasons that was forced to expend inordinate sums of capital on infrastructure simply to attempt to feed itself. Instead, the United States could exist in relative peace for its first few decades without needing to worry about any large-scale, omnipresent military or economic challenges, so it did not have to garrison a large military. Every scrap of energy the young country possessed could be spent on making itself more sustainable. When viewed together -- the robust natural transport network overlaying vast tracts of excellent farmland, sharing a continent with two much smaller and weaker powers -- it is inevitable that whoever controls the middle third of North America will be a great power.
With these basic inputs, the American polity was presented a set of imperatives it had to achieve in order to be a successful nation. They are only rarely declared elements of national policy, instead serving as a sort of subconscious set of guidelines established by geography that most governments -- regardless of composition or ideology -- find themselves following. The United States' strategic imperatives are presented here in five parts. Normally imperatives are pursued in order, but there is considerable time overlap between the first two and the second two.
1. Dominate the Greater Mississippi Basin
The early nation was particularly vulnerable to its former colonial master. The original 13 colonies were hardwired into the British Empire economically, and trading with other European powers (at the time there were no other independent states in the Western Hemisphere) required braving the seas that the British still ruled. Additionally, the colonies' almost exclusively coastal nature made them easy prey for that same navy should hostilities ever recommence, as was driven brutally home in the War of 1812 in which Washington was sacked.
There are only two ways to protect a coastal community from sea power. The first is to counter with another navy. But navies are very expensive, and it was all the United States could do in its first 50 years of existence to muster a merchant marine to assist with trade. France's navy stood in during the Revolutionary War in order to constrain British power, but once independence was secured, Paris had no further interest in projecting power to the eastern shore of North America (and, in fact, nearly fought a war with the new country in the 1790s).
The second method of protecting a coastal community is to develop territories that are not utterly dependent upon the sea. Here is where the United States laid the groundwork for becoming a major power, since the strategic depth offered in North America was the Greater Mississippi Basin.
Achieving such strategic depth was both an economic and a military imperative. With few exceptions, the American population was based along the coast, and even the exceptions -- such as Philadelphia -- were easily reached via rivers. The United States was entirely dependent upon the English imperial system not just for finished goods and markets but also for the bulk of its non-agricultural raw materials, in particular coal and iron ore. Expanding inland allowed the Americans to substitute additional supplies from mines in the Appalachian Mountains. But those same mountains also limited just how much depth the early Americans could achieve. The Appalachians may not be the Swiss Alps, but they were sufficiently rugged to put a check on any deep and rapid inland expansion. Even reaching the Ohio River Valley -- all of which lay within the initial territories of the independent United States -- was largely blocked by the Appalachians. The Ohio River faced the additional problem of draining into the Mississippi, the western shore of which was the French territory of Louisiana and all of which emptied through the fully French-held city of New Orleans.
The United States solved this problem in three phases. First, there was the direct purchase of the Louisiana Territory from France in 1803. (Technically, France's Louisiana Territory was Spanish-held at this point, its ownership having been swapped as a result of the Treaty of Paris in 1763 that ended the Seven Years' War. In October 1800, France and Spain agreed in secret to return the lands to French control, but news of the transfer was not made public until the sale of the lands in question to the United States in July 1803. Therefore, between 1762 and 1803 the territory was legally the territory of the Spanish crown but operationally was a mixed territory under a shifting patchwork of French, Spanish and American management.)
At the time, Napoleon was girding for a major series of wars that would bear his name. France not only needed cash but also to be relieved of the security burden of defending a large but lightly populated territory in a different hemisphere. The Louisiana Purchase not only doubled the size of the United States but also gave it direct ownership of almost all of the Mississippi and Missouri river basins. The inclusion of the city of New Orleans in the purchase granted the United States full control over the entire watershed. Once the territory was purchased, the challenge was to develop the lands. Some settlers migrated northward from New Orleans, but most came via a different route.
The second phase of the strategic-depth strategy was the construction of that different route: the National Road (aka the Cumberland Road). This project linked Baltimore first to Cumberland, Md. -- the head of navigation of the Potomac -- and then on to the Ohio River Valley at Wheeling, W. Va., by 1818. Later phases extended the road across Ohio (1828), Indiana (1832) and Illinois (1838) until it eventually reached Jefferson City, Mo., in the 1840s. This single road (known in modern times as U.S. Route 40 or Interstate 70 for most of its length) allowed American pioneers to directly settle Ohio, Indiana, Illinois and Missouri and granted them initial access to Michigan, Wisconsin, Iowa and Minnesota. For the better part of a century, it was the most heavily trafficked route in the country, and it allowed Americans not only to settle the new Louisiana Territory but also to finally take advantage of the lands ceded by the British in 1787. With the road's completion, the original 13 colonies were finally lashed to the Greater Mississippi Basin via a route that could not be challenged by any outside power.
The third phase of the early American expansion strategy was in essence an extension of the National Road via a series of settlement trails, by far the most important and famous of which was the Oregon Trail. While less of a formal construction than the National Road, the Oregon Trail opened up far larger territories. The trail was directly responsible for the initial settling of Kansas, Nebraska, Wyoming, Idaho and Oregon. A wealth of secondary trails branched off from the main artery -- the Mormon, Bozeman, California and Denver trails -- and extended the settlement efforts to Montana, Colorado, Utah, Nevada and California. The trails were all active from the early 1840s until the completion of the country's first transcontinental railway in 1869. That project's completion reduced East Coast-West Coast travel time from six months to eight days and slashed the cost by 90 percent (to about $1,100 in 2011 dollars). The river of settlers overnight turned into a flood, finally cementing American hegemony over its vast territories.
Collectively, the Louisiana Purchase, the National Road and the Oregon Trail facilitated the largest and fastest cultural expansion in human history. From beginning to end, the entire process required less than 70 years. However, it should be noted that the last part of this process -- the securing of the West Coast -- was not essential to American security. The Columbia River Valley and California's Central Valley are not critical American territories. Any independent entities based in either could not possibly generate a force capable of threatening the Greater Mississippi Basin. This hardly means that these territories are unattractive or a net loss to the United States -- among other things, they grant the United States full access to the Pacific trading basin -- only that control of them is not imperative to American security.
2. Eliminate All Land-Based Threats to the Greater Mississippi Basin
The first land threat to the young United States was in essence the second phase of the Revolutionary War -- a rematch between the British Empire and the young United States in the War of 1812. That the British navy could outmatch anything the Americans could float was obvious, and the naval blockade was crushing to an economy dependent upon coastal traffic. Geopolitically, the most critical part of the war was the participation of semi-independent British Canada. It wasn't so much Canadian participation in any specific battle of the war (although Canadian troops did play a leading role in the sacking of Washington in August 1814) as it was that Canadian forces, unlike the British, did not have a supply line that stretched across the Atlantic. They were already in North America and, as such, constituted a direct physical threat to the existence of the United States.
Canada lacked many of the United States' natural advantages even before the Americans were able to acquire the Louisiana Territory. First and most obvious, Canada is far enough north that its climate is far harsher than that of the United States, with all of the negative complications one would expect for population, agriculture and infrastructure. What few rivers Canada has neither interconnect nor remain usable year round. While the Great Lakes do not typically freeze, some of the river connections between them do. Most of these river connections also have rapids and falls, greatly limiting their utility as a transport network. Canada has made them more usable via grand canal projects, but the country's low population and difficult climate greatly constrain its ability to generate capital locally. Every infrastructure project comes at a great opportunity cost, such a high cost that the St. Lawrence Seaway -- a series of locks that link the St. Lawrence River to the Great Lakes and allow full ocean access -- was not completed until 1959.
Canada is also greatly challenged by geography. The maritime provinces -- particularly Newfoundland and Prince Edward Island -- are disconnected from the Canadian landmass and unable to capitalize on what geographic blessings the rest of the country enjoys. They lack even the option of integrating south with the Americans and so are perennially poor and lightly populated compared to the rest of the country. Even in the modern day, what population centers Canada does have are geographically sequestered from one another by the Canadian Shield and the Rocky Mountains.
As time advanced, none of Canada's geographic weaknesses worked themselves out. Even the western provinces -- British Columbia, Alberta, Saskatchewan and Manitoba -- are linked to Canada's core by only a single transport corridor that snakes 1,500 kilometers through the emptiness of western and central Ontario north of Lake Superior. All four provinces have been forced by geography and necessity to be more economically integrated with their southern neighbors than with their fellow Canadian provinces.
Such challenges to unity and development went from being inconvenient and expensive to downright dangerous when the British ended their involvement in the War of 1812 in February 1815. The British were exhausted from the Napoleonic Wars in Europe and, with the French Empire having essentially imploded, were more interested in reshaping the European balance of power than re-engaging the Americans in distant North America. For their part, the Americans were mobilized, angry and -- remembering vividly the Canadian/British sacking of Washington -- mulling revenge. This left a geographically and culturally fractured Canada dreading a long-term, solitary confrontation with a hostile and strengthening local power. During the following decades, the Canadians had little choice but to downgrade their ties to the increasingly disinterested British Empire, adopt political neutrality vis-a-vis Washington, and begin formal economic integration with the United States. Any other choice would have put the Canadians on the path to another war with the Americans (this time likely without the British), and that war could have had only one outcome.
With its northern border secured, the Americans set about excising as much other extra-hemispheric influence from North America as possible. The Napoleonic Wars had not only absorbed British attention but had also shattered Spanish power (Napoleon actually succeeded in capturing the king of Spain early in the conflicts). Using a combination of illegal settlements, military pressure and diplomacy, the United States was able to gain control of east and west Florida from Madrid in 1819 in exchange for recognizing Spanish claims to what is now known as Texas (Tejas to the Spanish of the day).
This "recognition" was not even remotely serious. With Spain reeling from the Napoleonic Wars, Spanish control of its New World colonies was frayed at best. Most of Spain's holdings in the Western Hemisphere either had already established their independence when Florida was officially ceded, or -- as in Mexico -- were bitterly fighting for it. Mexico achieved its independence a mere two years after Spain ceded Florida, and the United States' efforts to secure its southwestern borders shifted to a blatant attempt to undermine and ultimately carve up the one remaining Western Hemispheric entity that could potentially challenge the United States: Mexico.
The Ohio and Upper Mississippi basins were hugely important assets, since they provided not only ample land for settlement but also sufficient grain production and easy transport. Since that transport allowed American merchants to easily access broader international markets, the United States quickly transformed itself from a poor coastal nation to a massively capital-rich commodities exporter. But these inner territories harbored a potentially fatal flaw: New Orleans. Should any nation but the United States control this single point, the entire maritime network that made North America such valuable territory would be held hostage to the whims of a foreign power. This is why the United States purchased New Orleans.
But even with the Louisiana Purchase, owning was not the same as securing, and all the gains of the Ohio and Louisiana settlement efforts required the permanent securing of New Orleans. Clearly, the biggest potential security threat to the United States was newly independent Mexico, the border with which was only 150 kilometers from New Orleans. In fact, New Orleans' security was even more precarious than such a small distance suggested.
Most of eastern Texas was forested plains and hills with ample water supplies -- ideal territory for hosting and supporting a substantial military force. In contrast, southern Louisiana was swamp. Only the city of New Orleans itself could house forces, and they would need to be supplied from another location via ship. It did not require a particularly clever military strategy for one to envision a Mexican assault on the city.
The United States defused and removed this potential threat by encouraging the settlement of not just its own side of the border region but the other side as well, pushing until the legal border reflected the natural border -- the barrens of the desert. Just as the American plan for dealing with Canada was shaped by Canada's geographic weakness, Washington's efforts to first shield against and ultimately take over parts of Mexico were shaped by Mexico's geographic shortcomings.
In the early 1800s Mexico, like the United States, was a very young country and much of its territory was similarly unsettled, but it simply could not expand as quickly as the United States for a variety of reasons. Obviously, the United States enjoyed a head start, having secured its independence in 1783 while Mexico became independent in 1821, but the deeper reasons are rooted in the geographic differences of the two states.
In the United States, the cheap transport system allowed early settlers to quickly obtain their own small tracts of land. It was an attractive option that helped fuel the early migration waves into the United States and then into the continent's interior. Growing ranks of landholders exported their agricultural output either back down the National Road to the East Coast or down the Ohio and Mississippi rivers and on to Europe. Small towns formed as wealth collected in the new territories, and in time the wealth accumulated to the point that portions of the United States had the capital necessary to industrialize. The interconnected nature of the Midwest ensured sufficient economies of scale to reinforce this process, and connections between the Midwest and the East Coast were sufficient to allow advances in one region to play off of and strengthen the other.
Mexico, in contrast, suffered from a complete lack of navigable rivers and had only a single good port (Veracruz). Additionally, what pieces of arable land it possessed were neither collected into a singular mass like the American interior nor situated at low elevations. The Mexico City region is arable only because it sits at a high elevation -- at least 2,200 meters above sea level -- lifting it out of the subtropical climate zone that predominates at that latitude.
This presented Mexico with a multitude of problems. First and most obviously, the lack of navigable waterways and the non-abundance of ports drastically reduced Mexico's ability to move goods and thereby generate its own capital. Second, the disassociated nature of Mexico's agricultural regions forced the construction of separate, non-integrated infrastructures for each individual sub-region, drastically raising the costs of even basic development. There were few economies of scale to be had, and advances in one region could not bolster another. Third, the highland nature of the Mexico City core required an even more expensive infrastructure, since everything had to be transported up the mountains from Veracruz. The engineering challenges and costs were so extreme and Mexico's ability to finance them so strained that the 410-kilometer railway linking Mexico City and Veracruz was not completed until 1873. (By that point, the United States had two intercontinental lines and roughly 60,000 kilometers of railways.)
The higher cost of development in Mexico resulted in a very different economic and social structure compared to the United States. Instead of small landholdings, Mexican agriculture was dominated by a small number of rich Spaniards (or their descendants) who could afford the high capital costs of creating plantations. So whereas American settlers were traditionally yeoman farmers who owned their own land, Mexican settlers were largely indentured laborers or de facto serfs in the employ of local oligarchs. The Mexican landowners had, in essence, created their own company towns and saw little benefit in pooling their efforts to industrialize. Doing so would have undermined their control of their economic and political fiefdoms. This social structure has survived to the modern day, with the bulk of Mexican political and economic power held by the same 300 families that dominated Mexico's early years, each with its local geographic power center.
For the United States, the attraction of owning one's own destiny made it the destination of choice for most European migrants. At the time that Mexico achieved independence it had 6.2 million people versus the U.S. population of 9.6 million. In just two generations -- by 1870 -- the American population had ballooned to 38.6 million while Mexico's was only 8.8 million. This U.S. population boom, combined with the United States' ability to industrialize organically, not only allowed it to develop economically but also enabled it to provide the goods for its own development.
The American effort against Mexico took place in two theaters. The first was Texas, and the primary means was settlement as enabled by the Austin family. Most Texas scholars begin the story of Texas with Stephen F. Austin, considered to be the dominant personality in Texas' formation. Stratfor starts earlier with Stephen's father, Moses Austin. In December 1796, Moses relocated from Virginia to then-Spanish Missouri -- a region that would, within a decade, become part of the Louisiana Purchase -- and began investing in mining operations. He swore fealty to the Spanish crown but obtained permission to assist with settling the region -- something he did with American, not Spanish, citizens. Once Missouri became American territory, Moses shifted his attention south to the new border and used his contacts in the Spanish government to replicate his Missouri activities in Spanish Tejas.
After Moses' death in 1821, his son took over the family business of establishing American demographic and economic interests on the Mexican side of the border. Whether the Austins were American agents or simply profiteers is irrelevant; the end result was an early skewing of Tejas in the direction of the United States. Stephen's efforts commenced the same year as his father's death, which was the same year that Mexico's long war of independence against Spain ended. At that time, Spanish/Mexican Tejas was nearly devoid of settlers -- Anglo or Hispanic -- so the original 300 families that Stephen F. Austin helped settle in Tejas immediately dominated the territory's demography and economy. And from that point on the United States not so quietly encouraged immigration into Mexican Tejas.
Once Tejas' population identified more with the United States than it did with Mexico proper, the hard work was already done. The remaining question was how to formalize American control, no small matter. When hostilities broke out between Mexico City and these so-called "Texians," U.S. financial interests -- most notably the U.S. regional reserve banks -- bankrolled the Texas Revolution of 1835-1836.
It was in this war that one of the most important battles of the modern age was fought. After capturing the Alamo, Mexican dictator Gen. Antonio Lopez de Santa Anna marched north and then east with the intention of smashing the Texian forces in a series of engagements. With the Texians outnumbered by a factor of more than five to one, there was every indication that the Mexican forces would prevail over the Texian rebels. But with no small amount of luck the Texians managed not only to defeat the Mexican forces at the Battle of San Jacinto but also capture Santa Anna himself and force a treaty of secession upon the Mexican government. An independent Texas was born and the Texians became Texans.
However, had the battle gone the other way the Texian forces would not have simply been routed but crushed. It was obvious to the Mexicans that the Texians had been fighting with weapons made in the United States, purchased from the United States with money lent by the United States. Since there would have been no military force between the Mexican army and New Orleans, it would not have required a particularly ingenious plan for Mexican forces to capture New Orleans. It could well have been Mexico -- not the United States -- that controlled access to the North American core.
But Mexican supremacy over North America was not to be, and the United States continued consolidating. The next order of business was ensuring that Texas neither fell back under Mexican control nor was able to persist as an independent entity.
Texas was practically a still-born republic. The western half of Texas suffers from rocky soil and aridity, and its rivers are for the most part unnavigable. Like Mexico, its successful development would require a massive application of capital, and it attained its independence only by accruing a great deal of debt. That debt was owed primarily to the United States, which chose not to write off any upon conclusion of the war. Add in that independent Texas had but 40,000 people (compared to the U.S. population at the time of 14.7 million) and the future of the new country was -- at best -- bleak.
Texas immediately applied for statehood, but domestic (both Texan and American) political squabbles and a refusal of Washington to accept Texas' debt as an American federal responsibility prevented immediate annexation. Within a few short years, Texas' deteriorating financial position combined with a revenge-minded Mexico hard by its still-disputed border forced Texas to accede to the United States on Washington's terms in 1845. From that point the United States poured sufficient resources into its newest territory (ultimately exchanging approximately one-third of Texas' territory for the entirety of the former country's debt burden in 1850, giving Texas its contemporary shape) and set about enforcing the new U.S.-Mexico border.
Which brings us to the second part of the American strategy against Mexico. While the United States was busy supporting Texian/Texan autonomy, it was also undermining Spanish/Mexican control of the lands of what would become the American Southwest farther to the west. The key pillar of this strategy was another of the famous American trails: the Santa Fe.
Contrary to conventional wisdom, the Santa Fe Trail was formed not only before the New Mexico Territory became American, or even before Texas became an U.S. state, but before the territory become formally Mexican -- the United States founded the trail when Santa Fe was still held by Spanish authority. The trail's purpose was twofold: first, to fill the region on the other side of the border with a sufficient number of Americans so that the region would identify with the United States rather than with Spain or Mexico and, second, to establish an economic dependency between the northern Mexican territories and the United States.
The United States' more favorable transport options and labor demography granted it the capital and skills it needed to industrialize at a time when Mexico was still battling Spain for its independence. The Santa Fe Trail started filling the region not only with American settlers but also with American industrial goods that Mexicans could not get elsewhere in the hemisphere.
Even if the race to dominate the lands of New Mexico and Arizona had been a fair one, the barrens of the Chihuahuan, Sonoran and Mojave deserts greatly hindered Mexico's ability to settle the region with its own citizens. Mexico quickly fell behind economically and demographically in the contest for its own northern territories. (Incidentally, the United States attempted a similar settlement policy in western Canada, but it was halted by the War of 1812.)
The two efforts -- carving out Texas and demographically and economically dominating the Southwest -- came to a head in the 1846-1848 Mexican-American War. In that war the Americans launched a series of diversionary attacks across the border region, drawing the bulk of Mexican forces into long, arduous marches across the Mexican deserts. Once Mexican forces were fully engaged far to the north of Mexico's core territories -- and on the wrong side of the deserts -- American forces made an amphibious landing and quickly captured Mexico's only port at Veracruz before marching on and capturing Mexico City, the country's capital. In the postwar settlement, the United States gained control of all the lands of northern Mexico that could sustain sizable populations and set the border with Mexico through the Chihuahuan Desert, as good of an international border as one can find in North America. This firmly eliminated Mexico as a military threat.
3. Control the Ocean Approaches to North America
With the United States having not simply secured its land borders but having ensured that its North American neighbors were geographically unable to challenge it, Washington's attention shifted to curtailing the next potential threat: an attack from the sea. Having been settled by the British and being economically integrated into their empire for more than a century, the Americans understood very well that sea power could be used to reach them from Europe or elsewhere, outmaneuver their land forces and attack at the whim of whoever controlled the ships.
But the Americans also understood that useful sea power had requirements. The Atlantic crossing was a long one that exhausted its crews and passengers. Troops could not simply sail straight across and be dropped off ready to fight. They required recuperation on land before being committed to a war. Such ships and their crews also required local resupply. Loading up with everything needed for both the trip across the Atlantic and a military campaign would leave no room on the ships for troops. As naval technology advanced, the ships themselves also required coal, which necessitated a constellation of coaling stations near any theaters of operation. Hence, a naval assault required forward bases that would experience traffic just as heavy as the spear tip of any invasion effort.
Ultimately, it was a Russian decision that spurred the Americans to action. In 1821 the Russians formalized their claim to the northwest shore of North America, complete with a declaration barring any ship from approaching within 100 miles of their coastline. The Russian claim extended as far south as the 51st parallel (the northern extreme of Vancouver Island). A particularly bold Russian effort even saw the founding of Fort Ross, less than 160 kilometers north of San Francisco Bay, in order to secure a (relatively) local supply of foodstuffs for Russia's American colonial effort.
In response to both the broader geopolitical need as well as the specific Russian challenge, the United States issued the Monroe Doctrine in 1823. It asserted that European powers would not be allowed to form new colonies in the Western Hemisphere and that, should a European power lose its grip on an existing New World colony, American power would be used to prevent their re-entrance. It was a policy of bluff, but it did lay the groundwork in both American and European minds that the Western Hemisphere was not European territory. With every year that the Americans' bluff was not called, the United States' position gained a little more credibility.
All the while the United States used diplomacy and its growing economic heft to expand. In 1867 the United States purchased the Alaska Territory from Russia, removing Moscow's weak influence from the hemisphere and securing the United States from any northwestern coastal approach from Asia. In 1898, after a generation of political manipulations that included indirectly sponsoring a coup, Washington signed a treaty of annexation with the Kingdom of Hawaii. This secured not only the most important supply depot in the entire Pacific but also the last patch of land on any sea invasion route from Asia to the U.S. West Coast.
The Atlantic proved far more problematic. There are not many patches of land in the Pacific, and most of them are in the extreme western reaches of the ocean, so securing a buffer there was relatively easy. On the Atlantic side, many European empires were firmly entrenched very close to American shores. The British held bases in maritime Canada and the Bahamas. Several European powers held Caribbean colonies, all of which engaged in massive trade with the Confederacy during the U.S. Civil War. The Spanish, while completely ejected from the mainland by the end of the 1820s, still held Cuba, Puerto Rico and the eastern half of Hispaniola (the modern-day Dominican Republic).
All were problematic to the growing United States, but it was Cuba that was the most vexing issue. Just as the city of New Orleans is critical because it is the lynchpin of the entire Mississippi watershed, Cuba, too, is critical because it oversees New Orleans' access to the wider world from its perch on the Yucatan Channel and Florida Straits. No native Cuban power is strong enough to threaten the United States directly, but like Canada, Cuba could serve as a launching point for an extra-hemispheric power. At Spain's height of power in the New World it controlled Florida, the Yucatan and Cuba -- precisely the pieces of territory necessary to neutralize New Orleans. By the end of the 19th century, those holdings had been whittled down to Cuba alone, and by that time the once-hegemonic Spain had been crushed in a series of European wars, reducing it to a second-rate regional power largely limited to southwestern Europe. It did not take long for Washington to address the Cuba question.
In 1898, the United States launched its first-ever overseas expeditionary war, complete with amphibious assaults, long supply lines and naval support for which American warfighting would in time become famous. In a war that was as globe-spanning as it was brief, the United States captured all of Spain's overseas island territories -- including Cuba. Many European powers retained bases in the Western Hemisphere that could threaten the U.S. mainland, but with Cuba firmly in American hands, they could not easily assault New Orleans, the only spot that could truly threaten America's position. Cuba remained a de facto American territory until the Cuban Revolution of 1959. At that point, Cuba again became a launching point for an extra-hemispheric power, this time the Soviet Union. That the United States risked nuclear war over Cuba is a testament to how seriously Washington views Cuba. In the post-Cold War era Cuba lacks a powerful external sponsor and so, like Canada, is not viewed as a security risk.
After the Spanish-American war, the Americans opportunistically acquired territories when circumstances allowed. By far the most relevant of these annexations were the results of the Lend-Lease program in the lead-up to World War II. The United Kingdom and its empire had long been seen as the greatest threat to American security. In addition to two formal American-British wars, the United States had fought dozens of skirmishes with its former colonial master over the years. It was British sea power that had nearly destroyed the United States in its early years, and it remained British sea power that could both constrain American economic growth and ultimately challenge the U.S. position in North America.
The opening years of World War II ended this potential threat. Beset by a European continent fully under the control of Nazi Germany, London had been forced to concentrate all of its naval assets on maintaining a Continental blockade. German submarine warfare threatened both the strength of that blockade and the ability of London to maintain its own maritime supply lines. Simply put, the British needed more ships. The Americans were willing to provide them -- 50 mothballed destroyers to be exact -- for a price. That price was almost all British naval bases in the Western Hemisphere. The only possessions that boasted good natural ports that the British retained after the deal were in Nova Scotia and the Bahamas.
The remaining naval approaches in the aftermath of Lend-Lease were the Azores (a Portuguese possession) and Iceland. The first American operations upon entering World War II were the occupations of both territories. In the post-war settlement, not only was Iceland formally included in NATO but its defense responsibilities were entirely subordinated to the U.S. Defense Department.
4. Control the World's Oceans
The two world wars of the early 20th century constituted a watershed in human history for a number of reasons. For the United States the wars' effects can be summed up with this simple statement: They cleared away the competition.
Global history from 1500 to 1945 is a lengthy treatise of increasing contact and conflict among a series of great regional powers. Some of these powers achieved supra-regional empires, with the Spanish, French and English being the most obvious. Several regional powers -- Austria, Germany, Ottoman Turkey and Japan -- also succeeded in extending their writ over huge tracts of territory during parts of this period. And several secondary powers -- the Netherlands, Poland, China and Portugal -- had periods of relative strength. Yet the two world wars massively devastated all of these powers. No battles were fought in the mainland United States. Not a single American factory was ever bombed. Alone among the world's powers in 1945, the United States was not only functional but thriving.
The United States immediately set to work consolidating its newfound power, creating a global architecture to entrench its position. The first stage of this -- naval domination -- was achieved quickly and easily. The U.S. Navy at the beginning of World War II was already a respectable institution, but after three years fighting across two oceans it had achieved both global reach and massive competency. But that is only part of the story. Equally important was the fact that, as of August 1945, with the notable exception of the British Royal Navy, every other navy in the world had been destroyed. As impressive as the United States' absolute gains in naval power had been, its relative gains were grander still. There simply was no competition. Always a maritime merchant power, the United States could now marry its economic advantages to absolute dominance of the seas and all global trade routes. And it really didn't need to build a single additional ship to do so (although it did anyway).
Over the next few years the United States' undisputed naval supremacy allowed the Americans to impose a series of changes on the international system.
- The formation of NATO in 1949 placed all of the world's surviving naval assets under American strategic direction.
- The inclusion of the United Kingdom, Italy, Iceland and Norway in NATO granted the United States the basing rights it needed to utterly dominate the North Atlantic and the Mediterranean -- the two bodies of water that would be required for any theoretical European resurgence. The one meaningful European attempt to challenge the new reality -- the Anglo-French Sinai campaign of 1956 -- cemented the downfall of the European navies. Both London and Paris discovered that they now lacked the power to hold naval policies independent of Washington.
- The seizure of Japan's Pacific empire granted the Americans basing access in the Pacific, sufficient to allow complete American naval dominance of the north and central portions of that ocean.
- A formal alliance with Australia and New Zealand extended American naval hegemony to the southern Pacific in 1951.
- A 1952 security treaty placed a rehabilitated Japan -- and its navy -- firmly under the American security umbrella.
Shorn of both independent economic vitality at home and strong independent naval presences beyond their home waters, all of the European empires quickly collapsed. Within a few decades of World War II's end, nearly every piece of the once globe-spanning European empires had achieved independence.
There is another secret to American success -- both in controlling the oceans and taking advantage of European failures -- that lies in an often-misunderstood economic structure called Bretton Woods. Even before World War II ended, the United States had leveraged its position as the largest economy and military to convince all of the Western allies -- most of whose governments were in exile at the time -- to sign onto the Bretton Woods accords. The states committed to the formation of the International Monetary Fund and World Bank to assist with the expected post-War reconstruction. Considering the general destitution of Western Europe at the time, this, in essence, was a U.S. commitment to finance if not outright fund that reconstruction. Because of that, the U.S. dollar was the obvious and only choice to serve as the global currency.
But Bretton Woods was about more than currency regimes and international institutions; its deeper purpose lay in two other features that are often overlooked. The United States would open its markets to participating states' exports while not requiring reciprocal access for its own. In exchange, participating states would grant the United States deference in the crafting of security policy. NATO quickly emerged as the organization through which this policy was pursued.
From the point of view of the non-American founders of Bretton Woods, this was an excellent deal. Self-funded reconstruction was out of the question. The bombing campaigns required to defeat the Nazis leveled most of Western Europe's infrastructure and industrial capacity. Even in those few parts of the United Kingdom that emerged unscathed, the state labored under a debt that would require decades of economic growth to recover from.
It was not so much that access to the American market would help regenerate Europe's fortunes as it was that the American market was the only market at war's end. And since all exports from Bretton-Woods states (which the exception of some Canadian exports) to the United States had to travel by water, and since the U.S. Navy was the only institution that could guarantee the safety of those exports, adopting security policies unfriendly to Washington was simply seen as a nonstarter. By the mid-1950s, Bretton Woods had been expanded to the defeated Axis powers as well as South Korea and Taiwan. It soon became the basis of the global trading network, first being incorporated into the General Agreement on Tariffs and Trade and in time being transformed into the World Trade Organization. With a single policy, the Americans not only had fused their economic and military policies into a single robust system but also had firmly established that American dominance of the seas and the global economic system would be in the interest of all major economies with the exception of the Soviet Union.
5. Prevent any Potential Challengers from Rising
From a functional point of view the United States controls North America because it holds nearly all of the pieces that are worth holding. With the possible exception of Cuba or some select sections of southern Canada, the rest of the landmass is more trouble than it is worth. Additionally, the security relationship it has developed with Canada and Mexico means that neither poses an existential threat to American dominance. Any threat to the United States would have to come from beyond North America. And the only type of country that could possibly dislodge the United States would be another state whose power is also continental in scope.
As of 2011, there are no such states in the international system. Neither are there any such powers whose rise is imminent. Most of the world is simply too geographically hostile to integration to pose significant threats. The presence of jungles, deserts and mountains and the lack of navigable rivers in Africa does more than make Africa capital poor; it also absolutely prevents unification, thus eliminating Africa as a potential seedbed for a mega-state. As for Australia, most of it is not habitable. It is essentially eight loosely connected cities spread around the edges of a largely arid landmass. Any claims to Australia being a "continental" power would be literal, not functional.
In fact, there are only two portions of the planet (outside of North America) that could possibly generate a rival to the United States. One is South America. South America is mostly hollow, with the people living on the coasts and the center dominated by rainforests and mountains. However, the Southern Cone region has the world's only other naturally interconnected and navigable waterway system overlaying arable land, the building blocks of a major power. But that territory -- the Rio de la Plata region -- is considerably smaller than the North American core and it is also split among four sovereign states. And the largest of those four -- Brazil -- has a fundamentally different culture and language than the others, impeding unification.
State-to-state competition is hardwired into the Rio de la Plata region, making a challenge to the United States impossible until there is political consolidation, and that will require not simply Brazil's ascendency but also its de facto absorption of Paraguay, Uruguay and Argentina into a single Brazilian superstate. Considering how much more powerful Brazil is than the other three combined, that consolidation -- and the challenge likely to arise from it -- may well be inevitable but it is certainly not imminent. Countries the size of Argentina do not simply disappear easily or quickly. So while a South American challenge may be rising, it is extremely unlikely to occur within a generation.
The other part of the world that could produce a rival to the United States is Eurasia. Eurasia is a region of extremely varied geography, and it is the most likely birthplace of an American competitor that would be continental in scope. Geography, however, makes it extremely difficult for such a power (or a coalition of such powers) to arise. In fact, the southern sub-regions of Eurasia cannot contribute to such formation. The Ganges River Basin is the most agriculturally productive in the world, but the Ganges is not navigable. The combination of fertile lands and non-navigable waterways makes the region crushingly overpopulated and poor.
Additionally, the mountains and jungles of South and Southeast Asia are quite literally the world's most difficult terrain. The countries in these sub-regions cannot expand beyond their mountain boundaries and have yet to prove that they can unify the resources within their regions (with the India-Pakistan rivalry being the most obvious example of sub-regional non-unity). The lands of the Middle East are mostly desert with the bulk of the population living either near the coasts -- and thus very vulnerable to American naval power -- or in river valleys that are neither productive enough to support an agenda of power projection nor accessible enough to encourage integration into a larger whole. Only the Fertile Crescent has reliable agriculture, but that agriculture is only possible with capital- and labor-intensive irrigation. The region's rivers are not navigable, and its lands are split among three different states adhering to three different religions (and that excludes fractious Lebanon).
That leaves only the lands of northern Eurasia -- Europe, the former Soviet Union and China -- as candidates for an anti-American coalition of substance. Northern Eurasia holds even more arable land than North America, but it is split among three regions: the North European Plain, the Eurasian steppe and the Yellow River basin. Although the developed lands of the North European Plain and the Eurasian steppe are adjacent, they have no navigable waterways connecting them, and even within the North European Plain none of its rivers naturally interconnects.
There is, however, the potential for unity. The Europeans and Russians have long engaged in canal-building to achieve greater economic linkages (although Russian canals linking the Volga to the sea all freeze in the winter). And aside from the tyranny of distance, there are very few geographic barriers separating the North European Plain from the Eurasian steppe from the Yellow River region, allowing one -- theoretically -- to travel from Bordeaux to the Yellow Sea unimpeded.
And so the final imperative of the dominant power of North America is to ensure that this never happens -- to keep Eurasia divided among as many different (preferably mutually hostile) powers as possible.
The United States does this in two ways. First, the United States grants benefits to as many states as possible for not joining a system or alliance structure hostile to American power. Bretton Woods (as discussed above under the fourth imperative) is the economic side of this effort. With it the United States has largely blunted any desire on the part of South Korea, Japan and most of the European states from siding against the United States in any meaningful way.
The military side of this policy is equally important. The United States engages in bilateral military relationships in order to protect states that would normally be swallowed up by larger powers. NATO served this purpose against the Soviets, while even within NATO the United States has much closer cooperation with states such as the United Kingdom, Norway, Denmark, the Netherlands, Poland and Romania, which feel themselves too exposed to extra-NATO foes (most notably Russia) or even intra-NATO allies (most notably Germany).
The United States has similar favored relationships with a broad host of non-European states as well, each of which feels physically threatened by local powers. These non-European states include Pakistan (concerned about India), Taiwan (China), South Korea (North Korea, China and Japan), Mongolia (China and Russia), Thailand (China, Myanmar and Vietnam), Singapore (Malaysia and Indonesia), Indonesia (China), Australia (China and Indonesia), Georgia (Russia), the United Arab Emirates and Qatar (Saudi Arabia and Iran), Saudi Arabia (Iran), Israel (the entire Muslim world), Jordan (Israel, Syria and Iraq) and Kuwait (Iran, Iraq and Saudi Arabia).
The second broad strategy for keeping Eurasia divided is direct intervention via the United States' expeditionary military. Just as the ability to transport goods via water is far cheaper and faster than land, so, too, is the ability to transport troops. Add in American military dominance of the seas and the United States has the ability to intervene anywhere on the planet. The United States' repeated interventions in Eurasia have been designed to establish or preserve a balance of power or, to put it bluntly, to prevent any process on Eurasia from resulting in a singular dominating power. The United States participated in both world wars to prevent German domination, and then bolstered and occupied Western Europe during the Cold War to prevent complete Russian dominance. Similarly, the primary rationale for involvement in Korea and Vietnam was to limit Russian power.
Even the ongoing conflicts in Afghanistan and Iraq should be viewed in this light. Al Qaeda, the Islamist militant group behind the 9/11 attacks, espoused an ideology that called for the re-creation of the caliphate, a pan-national religious-political authority that would have stretched from Morocco to the Philippines -- precisely the sort of massive entity whose creation the United States attempts to forestall. The launching of the war in Afghanistan, designed to hunt down al Qaeda's apex leadership, obviously fits this objective. As for Iraq, one must bear in mind that Saudi Arabia funded many of al Qaeda's activities, Syria provided many of its recruits and Iran regularly allowed free passage for its operatives. The United States lacked the military strength to invade all three states simultaneously, but in invading Iraq it made clear to all three what the continued price of sponsoring al Qaeda could be. All three changed their policies vis-a-vis al Qaeda as a result, and the recreation of the caliphate (never a particularly likely event) became considerably less likely than it was a decade ago.
But in engaging in such Eurasian interventions -- whether it is World War II or the Iraq War -- the United States finds itself at a significant disadvantage. Despite controlling some of the world's richest and most productive land, Americans account for a very small minority of the global population, roughly 5 percent, and at no time has more than a few percent of that population been in uniform (the record high was 8.6 percent during World War II). While an expeditionary military based on maritime transport allows the United States to intervene nearly anywhere in the world in force in a relatively short time frame, the need to move troops across the oceans means that those troops will always be at the end of a very long supply chain and operating at a stark numerical disadvantage when they arrive.
This prods the United States to work with -- or ideally, through -- its allies whenever possible, reserving American military force as a rarely used trump card. Note that in World Wars I and II the United States was not an early participant, instead becoming involved three years into each conflict when it appeared that one of the European powers would emerge victorious over the others and unify Europe under its control. Washington could not allow any country to emerge dominant. In the Cold War the United States maintained front-line forces in Western Europe and South Korea in case of hostilities, but it did so only under the rubric of an alliance structure that placed its allies directly in harm's way, giving those allies as much -- if not more -- reason to stand against U.S. foes. In many ways it allowed the reapplication of the U.S. strategy in the world wars: allow both sides to exhaust each other, and then join the conflict and collect the winnings with (by comparison) minimal casualties.
The strategy of using its allies as bulwarks has granted the United States such success that post-Cold War Washington has been able to reduce the possibility of regional hegemons emerging. Examples include the backing of the Kosovar Albanians and Bosniacs against Serbia in the 1990s Yugoslav wars and Operation Desert Storm in 1991. Ongoing efforts to hamstring Russia -- Ukraine's 2004-2005 Orange Revolution, for example -- should also be viewed in this light.