To build on jcustis's question, is the main effect of opposition that it supports the enemy directly or that it erodes support at home?

Certainly Bacevich is entitled to his opinion, any media outlet is entitled to publish it, and anyone is entitled to oppose it. Perhaps his best know published work ,"The New American Militarism: How Americans Are Seduced by War," was pretty polarizing when it was published a couple of years ago, as mentioned in an above posting. It is among a body of newer writings expounding on the virtues of isolationism. It would be nice to redeploy behind our oceans and pull up the drawbridge, but that didn't work between the World Wars and is even less like to work in an ever more globalized international environment.