In WW2, we had a strong isolationist element on the right, too, but that is a different story with different, pro-American origins, and it is mostly out of the picture now, with the exception of the (fringe) Ron Paul types. The consensus on the right and in the center is that the US must be a global power--not for imperial gain, but to spread free market capitalism for our own security. Free nations do not attack each other; they make each other richer.
The consensus on the left is that the US should be a global power, too. Make no mistake, if an Obama won, he would, like Clinton, use American power, but he would use it in ways that HARM America's interests, like Clinton did in Serbia. Yeah, we need to creat more Muslim states in Europe. Good work. A socialist America would exert its power to bring rogue states like Australia, Taiwan, and Chile into line. Breakaway movements in Spain, the Balkans, Central America, Columbia, the Philippines, Thailand, North Africa, etc. would be supported by the US, so that more Anti-American regimes could emerge. Any Muslim grievances would be nursed, since Islam is profoundly anti-western civilization, and the left needs to destroy western civilization in order to create its utopia.
In any event, the left is pro-war, just not pro-America.
Thanks for your post. It is unfortunate that we are back to having to deal with the Russian bear again. We have too lazily defended the victory in the cold war, and now it turns out to be a lull, not a victory. Very sad.