These two men were Joseph Stalin, the leader of Soviet Russia, and King Michael of Romania.
Michael instigated a coup against the government who fought alongside the Nazi regime, and that decision is said to have shortened the war by six months. Romania eventually became an ally of the United States, Great Britain and Soviet Russia.
Stalin forced Michael's abdication after the war. Michael proved to be a popular King, and some people in Romania would like to see his return as a constitutional monarch.
However, Stalin was the leader of a country which was pivotal in the war and viewed by both Great Britain and America as vital to stopping Hitler and the Nazis. Stalin also believed that Hitler would never attack him. The Nazis did do this, and with Romania and Hungary as allies, tried to fight the Soviet Army.
Stalin's involvement was important because it allowed more time for the British and Americans to gain some territory in Western Europe and fight the Nazis on the Western front. However, Stalin was important enough in his own right to gain control of Romania, and much of Eastern Europe.
Stalin did not have much interest in Transylvania, but he was interested in oil, and Romania and Transylvania had a lot of it.