After the German invasion in 1941, the USSR declared to be the defender of the Slavic nations occupied by Germany. It did not defend their allies, Czechoslovakia and Yugoslavia, against the Germans in the 1938-1941. In alliance with Germans it attacked Poland in 1939. Soviets used the Slavic idea to organize armed resistance in occupied nations. After the war, the Soviet Union intended to make them politically and militarily dependent. The Polish government rejected participation in the Soviet Slavic bloc. In the Polish political emigration and in the occupied country the Slavic idea was really popular, but as an anti-Soviet idea. Poland not the Soviet Union was expected to become the head of Slavic countries in Central and South-Eastern Europe.