if you look at what the etymology of peace it actually means lack of war or stability under one dominant nation. So peace then always occurs after wars
"Ok, so how about if everybody chooses war. Is war then peace?"
if everybody wanted war and waged it willingly and were happy with it i dont see what the problem would be I'm sure people would be "At peace" with their war, kind of like how you can "find peace" at your death bed..
Everybody in the world wanting war and wanting to die is an absurd thing to say, because it would never happen. Nobody ever wants war i don't think, nobody has ever started a war thinking, "I want war" they think, "I want objects/land/property/wealth/power", sometimes people even want "Peace" from war, from another place. Hence, war occurs from conflicts of interest, usually conflicts of self-interest.