<human>:  Why did the Soviet Union and the German Empire sign the Pact?
<bot>: The Soviet Union and Germany signed the Pact in order to prevent the spread of communism. The Brest–Litovsk Pact was signed on 3 March 1918 and it led to the end of World War I. The Pact stated that the two countries would exchange land for peace, but Germany was not interested in peace and they attacked the Soviet Union in June of that year.