Yes indeed, for much of the anti-war side, the war we are in is never as good as the last war we fought or the potential war against the "real" threat we aren't fighting. And that is always true, even of the last war or the next war against the now-potential threat.
They are the Goldilocks warriors. Always looking for the war not too soft and not too hard. Not too hot and not too cold:
Some people will just never support the war we are in right now. I doesn't matter what the war is at the moment.
They will cover their opposition by saying they supported a past war that we won (or even a lost war) even when they opposed such wars at the time. Just listen to those who now claim that they supported the Gulf War or Afghanistan campaign or who even respect the soldiers who fought in Vietnam. It's just this war in Iraq they oppose.
They may even say that another problem is more severe and must be met first--possibly with force--before waging the war in question. North Korea and Iran spring to mind. But you can always be sure that if the issue they once said is more important comes up, there will be another problem that must be dealt with first.
Whether too hot or too cold, the question of a war to defend us is never just right.
They never find the good war of their dreams. And never will. Well, they never will under a Republican president. But that's another issue they need to work through.
