I think it's gonna end with another World War 1. That broke out in an era wherein the world economy was actually more integrated than today's (thx to the British Empire.)

Kaiser Wilhelm II was a cousin of George V. He was such a close relative, if the current non-sexist rules for succession to the UK Throne were in place when Queen Victoria died Wilhelm would have been King-emperor of Britain as well as with Emperor of Germany.

More generally, the European Royals were all blood relations. Hence, a theory about the purported obsolescence of war: blood relations don't fight blood relations. That theory, along with the theory that global integration of the economy made war senseless, failed to survive WW1.

If there is to be another World War, odds are it'll be with China because of the Thucydides Trap.