The never-utilized CIA program of creating assassination teams, shut down by the Obama administration, should be revived and expanded. Even the current administration accepts the utility of assassination as a weapon against our terrorist enemies. Obama has expanded and escalated the drone assassination program which strikes at suspected Al Qaeda targets in Afghanistan and Pakistan. Despite the clumsy nature of such operations, the misidentifications and incorrect targeting, the regular collateral damage to innocent civilians, and the risk of destabilization to Pakistan, we persist in using such methods, because they represent one of the few ways to strike directly at our enemy's leaders.
Teams of assassins and individual operators would be a potent weapon in the type of asymmetric warfare involved in fighting nebulous terrorist enemies, who often do not present good targets for conventional military operations. Using the military is expensive, public, and is often overkill, creating more problems than it solves. A bullet through the brain or the heart of key individuals is cheaper, cleaner, and could be more effective.
Deploying assassins to kill terrorist enemies is something we should already be doing, and should have put into place right after 9/11. It is also worth considering directly targeting radical Islamic clerics who preach jihad against Americans and openly support terrorism. Such clerics believe they can inspire terrorism and send suicide bombers to their deaths with impunity, remaining secure themselves while others blow up civilians or install roadside bombs. It's time they started dying also.