The war didn't just contribute, it caused the division. The victorious Allies (U.S., U.K., France, and the Soviet Union) met at the end of WW2 to plan Germany's occupation and eventual reconstruction. The country was divided into four zones, each occupied by the forces of one of the victors. Berlin was similarly divided into four parts. In addition, the two "arms" that made up the easternmost part of the Third Reich were taken away and ceded to Poland, and the separate state of East Prussia was split between Poland and the Soviet Union. The 3 western powers agreed to reunite their sectors once democracy was established. However the Soviet Union, then ruled by Josef Stalin, refused to allow democratic reforms in its sector and instead established a so-called "People's Republic" in eastern Germany, along with similar puppet states in the other eastern European countries it had conquered. The result was the creation of two Germanys, the western Federal Republic (or BDR, for Bundesrepublik Deutschland in German) and the eastern German Democratic Republic (or DDR, Deutsche Demokratische Republik). The word "democratic" was of course part of the Orwellian Newspeak terminology that the Soviets used when naming their newly-established client dictatorships. That division persisted until the revolution of 1989-90 when the Berlin Wall fell and the DDR collapsed under the weight of public dissent and economic stagnation. There's much more information available in any decent European history book. Just visit your local library.