The post-war Red Scare
Why Did Fear of Communism Grip America After 1945?
When the Second World War ended in 1945, Americans expected peace. Instead, a new and invisible enemy emerged: Communism. The Soviet Union, America’s wartime ally, was rapidly expanding its control over Eastern Europe. In 1949 it tested its first atomic bomb. That same year, Communist forces under Mao Zedong took power in China. To many Americans, Communism seemed to be advancing everywhere — and they feared it could infiltrate their own country from within.
Between 1947 and 1950, a series of shocks deepened the Red Scare: the Soviet atomic test (August 1949), the ‘loss’ of China to Communism (October 1949), the conviction of Alger Hiss for perjury (January 1950) and the start of the Korean War (June 1950).
Truman’s Loyalty Order and HUAC
President Harry Truman responded in March 1947 by issuing Executive Order 9835, known as the Loyalty Order. It required loyalty checks on all federal employees. Over the next five years, around 3 million government workers were investigated and several thousand dismissed or resigned. Truman wanted to head off Republican accusations that his administration was ‘soft’ on Communism.
Congress already had the HUAC — the House Un-American Activities Committee — which had been investigating radical organisations since 1938. In 1947 HUAC turned its attention to Hollywood, calling 19 screenwriters and directors to testify. Ten of them — the “Hollywood Ten” — refused to answer questions, citing the First Amendment. They were cited for contempt of Congress and jailed. Their names appeared on the Hollywood blacklist, ending their careers.
One of HUAC’s most dramatic moments came in August 1948. Whittaker Chambers, a former Soviet spy who had defected, testified that Alger Hiss — a senior State Department official — had passed him secret documents in the 1930s. Hiss denied it. A young Republican congressman named Richard Nixon pushed the investigation hard. Hiss was convicted of perjury in January 1950 and sentenced to five years in prison. The case convinced many Americans that Communists had reached the highest levels of government.
J. Edgar Hoover and the FBI
J. Edgar Hoover was the most powerful domestic security figure of the era. As FBI director, he had been building files on suspected radicals since the 1920s. From the late 1940s he fed information about suspected Communists to HUAC and to journalists, helping to shape public anxiety. Hoover believed that any association with the Communist Party — even a long-past membership — made a person a security risk. He testified frequently before Congress and cultivated a reputation as America’s indispensable anti-Communist guardian.
It is important to distinguish J. Edgar Hoover from Herbert Hoover, the president who served from 1929 to 1933. J. Edgar Hoover was never elected to anything — his power came from his position as FBI chief, which he held for 48 years.
In 1950 the FBI arrested Julius and Ethel Rosenberg, a New York couple, on charges of passing atomic bomb secrets to the Soviet Union. Julius had recruited a network of spies that included Ethel’s brother, David Greenglass, who worked at the Los Alamos nuclear laboratory. The Rosenbergs were convicted in March 1951 and executed on 19 June 1953 — the only American civilians executed for espionage during the Cold War. Their case polarised the country: supporters claimed the evidence against Ethel was thin and that antisemitism influenced the prosecution; opponents saw the death sentences as a necessary deterrent. Declassified Soviet intelligence documents (the Venona decrypts) later confirmed Julius’s espionage; historians still debate the extent of Ethel’s direct involvement.
J. Edgar Hoover was FBI Director from 1924 to 1972. He fed intelligence on suspected Communists to HUAC and journalists, helping to build public hysteria long before Senator McCarthy rose to prominence.
Media Campaigns and American Values
The government and private organisations used the media to highlight what they presented as the differences between American democracy and Soviet Communism. Radio broadcasts, films and pamphlets promoted free enterprise, religious faith and individual liberty as uniquely American virtues that Communism threatened. The McCarran Internal Security Act 1950 went further, requiring Communist and Communist-front organisations to register with the Justice Department and barring their members from certain federal jobs and passports.