Question

What led to the unraveling of the alliance between the Soviet Union and the United

States?
The U.S. was upset that Stalin initially signed a non-aggression pact with Hitler
and Germany in 1939.
The Soviet Union was upset that the U.S. did not invade German-occupied
Europe quick enough once they joined the war effort.
The death of FDR, who was a close ally and friend of Stalin, led to tensions
between Stalin and FDR's successor, Harry Truman, who was a strong anti-
communist.
All of the above

Answer 1

The correct answer is All of the above

The Axis countries (Germany, Italy and Japan) and the Allies (France, England, USA and, later, USSR) formed the alliances formed in World War II. After the end of the First World War, European countries sought ways so that the disputes that engendered this disastrous conflict would no longer be repeated.