This is not the first time in recent years that the United States has sought to draw up a list of Syrian government targets for a potential military strike. After all, the United States and its allies almost launched a considerable military operation following the 2013 Eastern Ghouta chemical weapons attack — the crossing of the now famous "red line" that brought the administration of then-President Barack Obama to the brink. Beyond the substantial attrition that the loyalist forces have suffered since then, there is one key factor that has completely altered the strategic picture for a U.S. strike in Syria. That is the arrival of the Russian military to Syria in 2015.
There was a significantly more comprehensive list of military options available to the United States in 2013; it has fewer options today in light of the Russian presence. The United States has to factor in the wide presence of Russian forces in Syria and can ill afford to accidentally kill Russian personnel in its retaliatory operation. The United States has no intention of starting an armed conflict with Russia, which would not only prove of far greater consequence than the conflict in Syria but which would also directly hinder the U.S. priority of fighting the Islamic State in Syria. To that end, the United States will have to be far more cautious and judicious in any military operation in Syria, and the options will necessarily be significantly more conservative than in 2013.
Limited Punitive Strikes
A limited punitive strike on government targets is the least risky option and the one requiring the fewest resources. This option would be meant to demonstrate U.S. credibility and to deter further loyalist use of chemical weapons by striking a select number of Syrian government targets, including command and control facilities and other high-value and symbolic targets. Punitive strikes can come in varying levels of intensity, duration, and scope, but they are essentially designed to send a message rather than to remove the Syrian government's ability to use chemical weapons.
In this scenario there are more possible targets than the United States would be interested in attacking. Command and control facilities would likely be the priority, driving home the message that the Syrian government leadership, particularly the military leadership, would pay for the decision to use chemical weapons. However, Syrian President Bashar al Assad himself would probably not be targeted because a strike on the upper leadership levels could quickly draw the United States into a full conflict, which it would want to avoid under this scenario. Specific facilities that may be targeted are the airport from where the Syrian aircraft carried out the chemical weapons attack and the specific headquarters of the commander who launched the operation.
Degrade the Government's Chemical Weapons Delivery Capability
Should the United States decide to take the mission a step further, it could also attempt to degrade Damascus' ability to use chemical weapons — not just discourage their use. The command, control and communication facilities could still be targeted, but the operation would also need to strike at a much wider network of targets and potentially even their associated defenses.
The mission would focus on the three main ways Damascus can deliver its chemical weapons: the air force, the ballistic missile force and the artillery force.
Although several government airfields have been neutralized or captured by the rebels, several others are still operational. There are at last six major Syrian airfields that are linked to the Syrian chemical weapons arsenal. To neutralize an airfield, the United States can crater the airfield, strike parked aircraft, destroy fuel and ammunition stores and disable ground control, radar and maintenance facilities.
Beyond the Syrian Air Force, other loyalist forces also possess large numbers of artillery and ballistic missiles that can be used to launch chemical weapons attacks. The United States however is highly unlikely to comprehensively go beyond air force targets since that would effectively commit the United States to a direct and full-scale war against the al Assad government, an option that is in all likelihood completely of the table at this point.
The Risk Factor
While the ranges of options available to the United States for a military response in Syria vary in risk, none of them are risk free. The dangers are many and long-term, ranging from loss of material and personnel to the triggering of an active conflict with Russia. Even assuming that a strike were carried out in a seamless fashion with little to no collateral damage, there would undoubtedly be consequences for U.S. operations in Syria. For one thing, the likelihood that the Syrian loyalists would seek to interfere with U.S. flight operations, or even ground activity in the country, would greatly increase, and even the deconfliction process with Russia will not survive unscathed. The bottom line is: There are no easy military options in Syria, and even the best run operation will inevitably lead to escalation and a multiplication of the miscalculation factors already present in such a convoluted conflict.