Just to put things into context, we had withdrawn our combat forces from the Republic of Vietnam in 1973 in accordance with the Paris Agreements. We turned everything over to the South Vietnamese; it was their war. We only had diplomatic representation and a minimum military presence after our combat units withdrew. Even so, the North Vietnamese were still hesitant to attack the South. They probed and probed in anticipation of immediate US intervention. When they saw that the US really was serious about staying out of their war, they then invaded in a final assault against South Vietnamese forces which culminated in the images we see today of the US embassy in Saigon being evacuated.

Killing does work. We killed over 3 million North Vietnamese soldiers and wiped out the Viet Cong completely. The problem is not with killing. The problem is with hesitation to kill. And this was our greatest downfall. We applied rules that limited our ability to hunt down and kill the enemy. And the enemy took full advantage of this and used those rules against us to avoid being killed and ultimately to kill us in return. We will probably disagree on this point; I'm used to it.

Just to clarify one thing: I don't know who said anything about killing terrorists indiscriminately. Nothing should ever be done indiscriminately. However, terrorists do fear being killed. They do not fear martyrdom. The key difference is that in one instance they've been "blessed" for death, in the other, they have not. Nobody wants to die in vain.