Why were the leaders of the us and the ussr able to create an anti-Hitler coalition?

The anti-Hitler coalition was created at the very beginning of the war. Then it included France, England and Poland. Then, when the war began on the eastern front, the USSR entered there. Then America also joined. They were able to create such a coalition because they fought against one enemy. Their priorities were to unite against a common enemy. The United States at that time began to supply food, weapons and other materials to the USSR.