Why did Churchill of Great Britain and Roosevelt of the United States not trust Stalin of the Soviet Union?
These western leaders saw Stalin as a pawn being used by a more diabolical Soviet leader that they did not trust.
These western leaders believed that Stalin had another agenda to fulfill and was just using the war to fulfill this agenda.
These western leaders were the head of democratic states and did not trust anyone who was a communist.
These western leaders did not trust anyone who was not educated in the West or had not been freely elected into office.