Would the US Actually Protect the Baltic States from Russia?

The Wikileaks cables have leaked a U.S.-NATO plan to defend the Baltic states of Latvia, Estonia, and Lithuania in case of a Russian attack.

But I have to ask, if Russia did in fact decide to invade the Baltics and reestablish their empire, is there a damn thing the U.S. would really do about it?

I have to think not. I don't think Americans care enough about tiny nations in eastern Europe to do anything more than boycott Russian goods or something. I'm not saying Americans still have a sort of Vietnam Syndrome after 9/11, but I really have trouble seeing any scenario where this happens unless the Russians decide they want Poland as well.

The Finnish would be mad because their cross-Baltic trips to buy massive amounts of cheap vodka would end. And, um, I can't think of any other nation would who care enough to really try to stop from retaking those nations.

Am I wrong about this?