Answer:
It was called the Warsaw Pact. The USSR and its allies created it in 1955 as a political and military alliance opposed to the US-led, Western alliance NATO. The Soviet Union took the decision to form the organization after the US and Western European announced the incorporation of West Germany into NATO. Beyond political motives, the Soviet Union had security concerns coming from that event . Memories of the Nazi invasion of 1941 were very fresh by then in Soviet minds.
Step-by-step explanation: