In February 1950, Senator Joseph McCarthy launched an anti-communist that lasted for more than four years. His attempts to unmask communists in the American administration and governmental agencies gave rise to actions that infringed on democratic procedure and civil liberties. As the Cold War grew, fear of communism at home and abroad meant that minorities were particularly under threat, as tensions and frustrations were channelled towards the handiest scapegoats. American Jewish organizations, who were having to come to terms with the Holocaust in Europe, were forced to contend with the real possibility of a serious anti-Semitic outburst at home. Jewish presence in the American Communist Party was conspicuous; although the overwhelming majority of Jewish Americans did not sympathise with its politics, there was concern that anti-communism would develop into anti-Semitism. McCarthy's anti-communist campaign endangered the very civil liberties that protected minorities, but criticism of McCarthy and his actions could be interpreted as support for communism. In order to convey the message that Jews were patriotic Americans concerned about both national security and civil liberties, Jewish organizations chose to present a united front, whilst also cooperating with non-sectarian American bodies. By doing so they professed an alternative anti-communism to the hardline McCarthy. This book sheds new light on McCarthy's attitudes to the Jews, to the Jewish organizations and to the Jewish individuals identified with communism.