At the end of World War 2 – the “big three” of the wartime alliance had become “the big two and a half” (Churchill’s own words).
The United States and the Soviet Union had emerged as superpowers. If the Soviets didn’t earn that title after Stalingrad, they certainly did after the battle of Kursk-Orel.
In my alternate history story “A Greater Britain” – I gave Great Britain a little bit more muscle and a bit more technology than they actually had.
For example I give them the Centurion Tank (with 17 pounder gun) long before they had it. I gave them the Vanguard class battleships HMS Vanguard and HMS Lion (the latter was never built) in time for the war and with 16 inch guns.
I also gave them the Gloster Meteor fighter jet earlier on and the Canberra jet bomber in time for the war and a few other things (such as an early Atomic Bomb, not long after the Americans).
Most important of all I gave them a mysterious new leader Cecile Tittington after Churchill died early in the conflict. A genius in both economic management and scientific and defence matters.
It all made for an interesting end to the war (Great Britain took Berlin before the Russians) and a somewhat different (tri-polar) post war world.