Contrary to the rhetoric of the Clinton administration and the Beltway Babblers, terrorism is not a criminal act in the ordinary sense.
Terrorism is a political act, a response to U.S. foreign policy.
It is an act of war waged by people too weak to have a conventional army or one large enough to take on the United States. Therefore, capturing an individual terrorist does not even address the problem. People who execute terrorist actions are expendable, replaceable soldiers. Catch one, kill one, and two will take his place. Because the terrorism is political, so, too, is the solution.