The best way to fight evil is to do some good. Let me qualify that—the best way to fight evil at home is to do some good. The best way to fight them abroad is to unleash the military.
So while I will never minimize the costs involved in military action, I am convinced that a failure to act in Libya would have carried a far greater price for America.
The military has no constant form, just as water has no constant shape - adapt as you face the enemy, without letting them know beforehand what you are going to do.