Countries that would have supported the United States: Britain, France, and Italy. These countries remained allied to the United States through the cold war and would have supported it in case of a war, since they were part of the NATO since its origin in 1949. NATO was an international military agreement created by the US to counterbalance the weight of the Soviet Union in the international arena.
Countries that would have supported the Soviet Union: Hungary, Albania, and Czechoslovakia. These countries were part of the Warsaw Pact, an international treaty signed in 1954 and led by the Soviet Union to stand against the NATO. Is important to note that Albania withdrew from the Warsaw pact in 1968.