Let's take a moment to recall Reagan's response to the terrorist bombings in Beirut:

I have asked Secretary of Defense Weinberger to present to me a plan for redeployment of the Marines from Beirut airport to their ships offshore. This redeployment will begin shortly and proceed in stages. U.S. military personnel will remain on the ground in Lebanon for training and equipping the Lebanese Army and protecting the remaining personnel. These are traditional functions that U.S. personnel perform in many friendly countries.

Interestingly, this response, as disgustingly Spanish as it appears in hindsight, didn't unleash a hellish cesspit of death on the American Homeland. I guess the terrorists who killed 241 Marines in 1983 just weren't as bloodthirsty as Mohammed Atta. After all, the underlying presumption behind a war of necessity is that without such a war, peace is not the alternative. The alternative is Hell. But there was neither war nor hell after Beirut. Which leads me to the conclusion that terrorism doesn't always necessitate war. Which is weird. Because that's obviously not true. Otherwise we wouldn't be at war against people who aren't terrorist because we really think they are terrorist that can only be appeased at the cost of, well...hell. Which we are.