All of these matters should proceed from the first question, what is America's national interest? This should be done, for example with respect to our relationship to Israel-a statement I know guaranteed generate us response from you-to determine if the relationship is worth the risk associated with it.
What do we gain from risking thermonuclear war over Crimea? Precious little that I can determine. What are the risks if our calculation goes wrong? Infinite!
Answer: don't be a party to this rodeo the game isn't worth the candle and we don't have to worry about what the parties who are involved are prepared to do or not do.
One cannot run from the world. Isolationism was tried in both previous world wars, and the “world” dragged us in notwithstanding. Showing weakness gets interpreted as being ripe for conquest.