However , on 22 June 1941 , Hitler unilaterally terminated the pact by invading the Soviet Union .
Hitler and Stalin had previously signed the Molotov -- Ribbentrop Pact which , on the face of it seemed to be advantageous to both .
On 22 June 1941 , Hitler unilaterally terminated the pact by invading the Soviet Union .
Hitler and Stalin had previously signed the Molotov -- Ribbentrop Pact which , on the face of it seemed to be advantageous to both .