From 1787 to 1865 the U.S. government was laissez-faire on economics too, but I don't see any great liberal nostalgia for that.

Isolationism is appealing to many people clean across the political spectrum. Listen to Pat Buchanan sometime. But I still don't think that it's realistic. With today's technology, I don't think we can hunker down behind our borders and let the world go to hell. And it would. I could come up with a long list of free countries that wouldn't be free right now if it weren't for the U.S., wisely or not, sticking its oar in.

As for weapons sales, I'd be the first to admit that we've armed some people who didn't deserve it, largely due to the wider arena of conflict with the Soviet Union. However, since the Soviets and Chinese had no scruples on this at all, I'm not sure what good prohibiting such sales would have done. It's usually not American weapons that are turning up in the hands of terrorists.