With the queasy U.S.-Soviet wartime alliance long dissolved into mutual suspicion, the House Un-American Activities Committee launched aggressive investigations of alleged communist activity in the Hollywood film industry in 1947--and again in 1951. Studio chiefs, terrified of scandal, scrambled to display their patriotism by producing anti-communist films, from melodramas to thrillers to animated cartoons. Twenty-one lively new essays by film historians examine the aesthetics and politics of more than 40 remarkable films of the McCarthy era and the chauvinism that spawned them.