Subversives: The FBI’s War on Student Radicals, and Reagan’s Rise to Power by Seth Rosenfeld Farrar, Straus and Giroux, 734 pp., $40.00

A curious thing about the United States is that anticommunism has always been far louder and more potent than communism. Unlike sister parties in France, Italy, India, and elsewhere, the Communist Party here has never controlled a major city or region, or even elected a single member to the national legislature. Henry Wallace’s Progressive Party in 1948 received no more than 2.4 percent of the popular vote with Communist support; and Wallace himself soon repudiated the Communists here and abroad.

American anticommunism, by contrast, built and destroyed thousands of careers; witch-hunted dissidents in Hollywood, universities, and government departments; and was a force that politicians like Joseph McCarthy and Richard Nixon rode to great prominence. Of course this was not the first time that heresy hunters have overshadowed the actual heretics: consider the Inquisition, which began before Martin Luther, the greatest heretic, was even born, or how, on accusations of Trotskyism, Stalin imprisoned or shot Soviets by the millions—numbers many times those of Trotsky’s beleaguered, faction-ridden actual followers. But heresy hunting is seldom really about ideas; it’s about maintaining power.

Power begins with surveillance, and the pioneer in American anti-Communist surveillance was Ralph Van Deman, whose elongated hawklike face made him someone a movie director would have cast for the job. A career US Army officer, Van Deman first made his mark keeping a close eye on Filipinos who might have the temerity to resist the long occupation of their country that began with the Spanish-American War. As the military intelligence chief in Manila starting in 1901, he used a web of undercover agents and the newest record-keeping technology—file cards—to track thousands of potential dissidents.

Later in his career, back in the United States, Van Deman filled his cards with the names of American socialists, labor activists, and supporters of the Russian Revolution, the sort of people rounded up in the notorious Palmer Raids of 1919–1920 that jailed some ten thousand leftists. He continued collecting information about Communists and other left-wingers long after he retired as a major general in 1929. With funding from the Army and J. Edgar Hoover’s new Federal Bureau of Investigation, he maintained a private network of informants until his death in 1952, keeping his 250,000 file cards in his house in San Diego, where they were frequently consulted by police Red squads and the FBI.1

It was Hoover, of course, who would take Van Deman’s search for real or imagined Communists to far greater heights. More than forty years after his death, we know a great deal about this unpleasant and power-hungry man, but the California investigative journalist Seth Rosenfeld adds significantly more in Subversives, which…