But war is not a game, and it is mott over when the whistle blows. Because there is no whistle. Not to say that what happens thirty years down the road is still part of the last war, but certainly occupation, settlement, demilitarization, installation of new government, etc., are.
Now, you may define terms in such a way as to restrict warfare to physical combat, in which case I must agree nation building came afterwards. But that’s not the way people talk, and anyway it’s not the conversation I want to have. If what comes after major combat operations is not war, let us call it “x” and agree the “x” if WWII was nation building.
I’m sorry, but that IS how people talk. The war ended when arms were put down and the vanquished accept whatever terms of the victor.
Everything AFTER that is not war.