From 1939 to 1945 how did the Soviets and Western Allies interact with one anoth

Question: From 1939 to 1945 how did the Soviets and Western Allies interact with one another!?

This is for a university level essay:

Discuss the wartime dealings of the Western allies and the Soviet Union from 1939 to 1945!. Include in your answer the various disputes that sometimes hindered cooperation among the powers as well as their efforts to construct a post-war settlement!.

I lost my course notes, so I think if I get enough basic answers here, I could start to pull more connections from my memory!.

ThanksWww@QuestionHome@Com

Best Answer - Chosen by Asker:

The only western allies in 1939 were France and Britain!.
The Soviet Union co-operated with Germany in the invasion of Poland!.
After western Europe was overun by the German Army in 1940 Britain was left alone as the only enemy of Germany!.
The Soviet Union was invaded by Hitler in June 1941 and became allied with Britain!.
Hitler declared war on the USA in December 1941 , two days after Pearl Harbor
The USA was useful in supplying men and materials for the later stages of the warWww@QuestionHome@Com