This year's Hajj to Mecca, Saudi Arabia, will present enormous security challenges -- and many opportunities for militants.

Hezbollah is aiming to expand its political power, ensure its long-term survival as a militant movement and serve Syrian interests in selecting Lebanon's new president. Meanwhile, with Iranian help, Hezbollah is recovering from the 2006 conflict with Israel and preparing for the next military confrontation with its foe.

There is no clear distinction in Russia between criminal enterprises and the government. In fact, criminal organizations and their leadership often have direct ties to oligarchs and others in positions of power.

Armed guards, armored vehicles and physical security devices can all be valuable protection tools, but they can be defeated by attackers who have planned an attack and then put it into play at the time and place of their choosing.

In the event of a U.S. attack against Iran, Tehran can be expected to include as part of its retaliatory strategy a militant organization it founded and has indoctrinated, funded, trained and equipped -- Hezbollah.

The intertwined drug and gun trade between Mexico and the United States is one of the reasons weapons are so prevalent in Mexico. Drug traffickers, criminal gangs and average citizens all have found ways to circumvent Mexico's strict gun-control laws.

Although the summer of 2007 was marked by threats and warnings of an imminent terrorist attack against the United States, no attack occurred. There are several reasons for this -- most notably the change in attitudes.

Beyond the military bureaucracy and the geopolitical processes acting upon it, another set of dynamics is behind the growing use of civilian contractors to protect diplomats in Iraq.

A federal jury in Sacramento, Calif., on Sept. 27 found radical environmental activist Eric McDavid guilty of conspiring to damage property by using explosives.

The annual U.N. General Assembly session in New York presents a significant security challenge to the U.S. government.