 At the end of September 1940, the Tripartite Pact united Japan, Italy and Germany to formalise the Axis Powers. The Tripartite Pact stipulated that any country, with the exception of the Soviet Union, not in the war which attacked any Axis Power would be forced to go to war against all three. The Axis expanded in November 1940 when Hungary, Slovakia and Romania joined the Tripartite Pact. Romania would make a major contribution (as did Hungary) to the Axis war against the USSR, partially to recapture territory ceded to the USSR, partially to pursue its leader Ion Antonescu's desire to combat communism.
