An increase in terror incidents involving Islamic radicals who are U.S. citizens is vexing law enforcement officials and posing new questions about the roots of their radicalization.

A profile of Egyptian Islamic Jihad, a militant Islamist group that is fully merged with al-Qaeda.

As military leaders in Washington revise their war strategy for Afghanistan, analysts say enlisting Afghan tribesmen could aid in security. Others warn that what helped stabilize Iraq may play very d…