Snowcroft's claptrap has a long history in American politics, but the source isn't 'Realism' in foreign policy.
This is simply Isolationism (Stay away from foreign entanglements)dressed up in new verbiage.
I agree that this is claptrap but at least he is honest. Liberals are for wars in Hatti and Kosovo but against the Iraq war. They position is incoherent (except it may just me anit-American).