The wave of publicity about Robert Hanssen, a veteran FBI agent who became a master spy for the Russians, brings to mind a far different man -- Whittaker Chambers, a veteran Soviet spy who became, in William F. Buckley Jr.'s words, "the most important American defector from communism."

April 1 marked the 100^th anniversary of Chambers' birth, though I'm sure few history students know it -- or even their teachers, which is a shame. Chambers' story is one of courage and faith that many can appreciate even in the post-Cold War era.

In August 1948, Chambers, an editor at Time magazine, identified Alger Hiss as a fellow member of his underground communist cell in the 1930s. Hiss immediately denied Chambers' charges. A golden boy of the liberal establishment, Hiss was a former assistant to the secretary of state, and the former general secretary of the United Nations founding conference in San Francisco. At the time, he was president of the Carnegie Endowment for International Peace.

Far more than reputations were at stake. If Hiss was innocent, anti-communism -- and the careers of those associated with it, like Richard Nixon, then a prominent communist-hunting congressman -- could take a deadly blow. If Hiss was guilty, anti-communism would become part of the political landscape and its spokesmen would become national leaders.

It took two trials, but Hiss was finally convicted of perjury for denying his pro-Soviet espionage activities and sentenced to five years in jail. Hiss went to his grave more than 40 years later still protesting his innocence -- and still lauded by many on the Left. But transcripts of secret Soviet messages sent during World War II, released in the mid-1990s, confirmed that Hiss had been a Soviet spy not only in the 1930s, but at least until 1945.

In 1952, Chambers published his magisterial, best-selling autobiography, "Witness." The work argued that America faced a crisis not of politics or economics but of faith. Secular liberalism, the dominant "ism" of the day, was a watered-down version of communism, Chambers insisted. Franklin Roosevelt's "New Deal" was radically "revolutionary" in its nature and its intentions.

All three themes, especially that the crisis of the 20th century was one of faith, resonated deeply with conservatives. Among those who agreed with and often quoted Chambers' uncompromising assessment was a one-time liberal turning conservative named Ronald Reagan.

"Witness" isn't easy reading. It's full of what Buckley called "Spenglerian gloom." But the work continues to have an impact almost a half century later. At a Washington dinner last November, retiring Sen. Bob Kerrey, D-Neb., admitted that reading "Witness" enabled him, for the first time in his life, to understand what communism really meant.

Chambers was a close friend and mentor of Buckley, founder of National Review, the most influential magazine in modern conservatism. Buckley invited Chambers to join his new publication in the 1950s, and Chambers demurred, pessimistic about its chances for success. But Buckley persuaded his friend to come aboard, arguing that "the culture of liberty deserves to survive" and have its own journal. One of Chambers' more memorable contributions was his evisceration of Ayn Rand's "Atlas Shrugged." His review, "Big Sister Is Watching You," helped bar conservatism's door to Rand's godless, technocratic ideas.

Chambers also was a private critic of Sen. Joe McCarthy. He told Buckley that the Wisconsin Republican was "a slugger and a rabble-rouser." Referring to McCarthy's broad, and sometimes questionable, accusations of people he thought were communists, Chambers said McCarthy was someone who "simply knows that somebody threw a tomato and the general direction from which it came."

Ironically, Chambers believed that he was probably leaving the winning side by denouncing communism. But he found reason to keep fighting against it for his children. As he recounts in "Witness," he once surveyed, on a cold night at his Maryland farm, the forces acting against him: The powerful establishment. The hostile press. The skeptical public and the lies lodged by Hiss partisans. He seriously considered suicide at that moment. Then his young son John came looking for him crying, "Papa! Papa! Don't ever go away."

"No, no, I won't ever go away," he said.

Chambers eventually did in July 1961 when he died. But for countless conservatives, he never has gone away, and he never will.

Lee Edwards is a senior fellow at The Heritage Foundation, and is the author of several books, including The Conservative Revolution: The Movement that Remade America.