Nobody who wins a war indulges in a bifurcated definition of victory. War is a political act; victory and defeat have meaning only in political terms. A country incapable of achieving its political objectives at an acceptable cost is losing the war, regardless of battlefield events.
Bifurcating victory (e.g. winning militarily, losing politically) is a useful salve for defeated armies. The "stab in the back" narrative helped take the sting out of failure for German generals after WWI and their American counterparts after Vietnam.
All the same, it's nonsense. To paraphrase Vince Lombardi, show me a political loser, and I'll show you a loser.