British empire sorta ended with WW2 tho. USA replaced Britain as the biggest world power, including Naval (thus trade) dominance. UK did rather fine despite it, because of the "special relationship" with their former colony, but the UK after WW2 was a lot less powerful and less dominant in the world than UK was before WW2... They for sure did not become a world power from it, they merely managed to sorta hold on to some of their "world power" status in the post WW2 world.