but I just think there is no way we could ever completely shut our doors.
How could we have sat by in 1992 and watched Kuwait be invaded and do nothing? Someone had to help (and many did). How could we have just sat by in the early 80s and watched Russia (our primary enemy at the time) walk into Afghanistan? That movie "Charlie Wilson's War" does a pretty good job showing both sides of that conflict from the American perspective. We helped tremendously by giving money and weapons to help the Afghans repel the Russians because we didn't want to fight them ourselves. However, we turned a blind eye to the difficulties the Afghans then faced rebuilding their country. The US was ok with spending a couple billion dollars to fight the fight, but was not willing to even spend one million to help rebuild schools.