Stalin’s “salami tactics” in Eastern Europe

Infiltration of the Manhattan Project and the spreading of nuclear secrets to the USSR led to suspicion that there was a Soviet spy embedded within the program

The descending of an “Iron Curtain” by Stalin across Europe (mentioned in a speech by Winston Churchill)

Wheeling Speech where Senator Joe McCarthy claimed to have a list of 200 communists in the U.S. State Department

Korean War & Chinese Civil War showed that communism was spreading across the world

Stalin’s brutal actions during the Berlin Blockade

The USSR’s first successful test of an atomic bomb (1949)

NSC-68 and the Kennan Telegram (the communists were aiming for “total destruction of rival power”)