Which of these groups was responsible for initiating the domestic anti-communist crusade in the late 1940s?

After World War 2 had finished and the Cold War had slowly started to become more of a threat to those in the US the government decided to take action. In March of 1947 President Harry Truman decided to issue what was known as the loyalty order which stated that all federal employees needed to be checked to make sure they were actually loyal to the US government and not working for the Soviet Union. This effect had a title and was known as the Red Scare. In conclusion the US government were the ones responsible for initiating the anti communist crusade.