You think that the US could play the army card against countries (allies) with troops in when the most spectacular failures of armed conflicts after WWII belong to the US (not least because how the US population relate to conflicts abroad, here including WWII as well)? Just to forget about the economic ties for a moment.

We are talking about a sub-set of security instruments and preventions, one of the many available, are we sure that an armed conflict - or just threat - would worth the trouble?