"winning" the war means accomplishing your political objectives. Those objectives may change as the war goes on, and in the case of Korea, the objective became "keep South Korea free from North Korean domination." That was achieved.

It was unclear to MacArthur and he assumed it was "destroy North Korea, whatever it takes." That became NOT the US objective, when it became clear that China stood in the way of it.

In Vietnam the objectives were never clearly laid out, but "keep South Vietnam free from North Vietnam domination" was pretty clearly it. Thus, we lost.

Your other points are wrong: the first Iraq war's objective was to eject Iraq from Kuwait. Perhaps that goal was insufficient, but that was the goal the military undertook, and achieved.

https://www.amazon.com/Strategy-Critical-Analysis-Vietnam-Wa...