No question U.S. policy is a hideous patchwork of inconsistency and hypocrisy. That's why these affairs need to be judged one at a time. The depredations of the author of a policy, or its inconsistency elsewhere, do not necessarily debunk the merits of a policy altogether.
Following your point, we could reason that since the U.S. did not intervene against Franco, it had no business moving against the Nazis.
I think a 'Hitler test' is useful. If an argument against U.S. intervention in the Balkans could be used to equal effect against the Normandy invasion, the argument should be rated as dubious. For perspective, it should be acknowledged that typically it is miniature Hitlers that are at issue these days.
Here's a trial run, based on some lava flowing from Carroll's volcano:
"Margaret, there is no such thing as a "right target" for U.S. military power. Is the U.S. attacking a fascist state? Hurrah for the fascists! Is the U.S. attacking a bunch of barbarians? Hurrah for the barbarians! Is the U.S. attacking a cadre of unreconstructed Stalinists? Hurrah for unreconstructed Stalinists! Is the U.S. attacking fascists disguised as Stalinists? Hurrah for fascists disguised as Stalinists."
This clearly fails the Hitler test. I do not mean that CC or anyone else here are in any way like Hitler or sympathetic with him. I mean their reasoning fails to distinguish among possible interventions or ways of intervening, in some cases by a failure to assess, or in the above case, as a matter of principle. Pacifist arguments clearly fail the test as well, though in most cases (excluding Hitler, of course) I would be sympathetic to them.
It could be that the U.S. policy comes a cropper, for many valid reasons that have been raised, but we are not led to any appreciation of this possibility if we reject its opposite -- the possibility of some kind of success -- on a priori grounds.
mbs