By that logic, we should have simply let Germany and Hitler bash each other's brains out, and stayed out of WWII
You mean Russia and Hitler. Too many ifs. And if the US did not provide aid to the UK and USSR, staying out of WW2, and if Hitler attacked the USSR before the UK and controls the Baltic, and then defeats the resource deficient UK and obtains its Navy and military, and allied with Japan, largely control the seas, as well as and the Middle East and Africa. And as the US has less incentive to develop its military than if it was fighting a two-front war, and the UK develops the A-bomb, then it controls the world.