Ler’s see, World War II started in 1931 (Pacific Theatre) and 1939 (European Theatre), though you can aruge it was one World War that started in 1914, and after a “between rounds” break fnished in 1945 (leaving assorted unfinished business such as Korea and the Middle East to fight about). The current war the US is in started in 2001, and shows no sign of ending, and has grown to include the entire Middle East and much of Africa.
So maybe if you are good at calculus (which deals with infinities and the like), you could tell us when there will be global peace?