In common usage, Joseph McCarthy's name has become synonymous with making groundless accusations, seeing enemies everywhere and chasing at phantoms. Even writers relatively sympathetic to the goals of the anti-communist crusade of the 1950s depict the Wisconsin senator who led it as a bully, a demagogue and a drunk. Arthur Herman, an adjunct professor of history at George Mason University in Virginia and the coordinator of the Western Civilization Program at the Smithsonian Institution, observes in his "Joseph McCarthy" that for today's commentators there's no risk in deriding McCarthy and little percentage in defending him: "McCarthy remains what the Germans would call vogelfrei -- the 'free bird' everyone and anyone is free to take a shot at, even 40 years after his death. Today he exists in most people's imagination almost solely as an established icon of evil."

Herman believes that's an unfair picture. If nothing else, it's an incomplete one because Americans had legitimate reasons to fear Soviet infiltration in the immediate postwar years. The United States and the Soviet Union were just about the only major powers left standing, their interests were bound to clash and there were nuclear weapons to worry about. Before and during the war, a substantial number of leftist intellectuals and institutions in the West were broadly supportive of the Soviet Union; lured in by the dreamy, "let's all share things" theory of communism, they ended up countenancing purges, show trials, political murders and intentional famines.

Herman certainly isn't the first to point that failure out -- or to argue that the apparatus of the Communist Party of the United States was basically under Stalin's control. Simply put, there was plenty of spying going on, and it seems that some of the people offering foreign-policy advice to U.S. leaders were willing to let parts of Europe and Asia fall under communist control. That might come as a surprise to those who learned everything they know about anti-communism from Arthur Miller, Hollywood and the Nation, but scholars who have studied declassified Soviet-bloc documents and other historical materials have been saying it for years.

Obviously, that doesn't mean that all or even most American communists were spies or in any position to influence American foreign policy, or that it was right to hound people because of their political beliefs. Even among hardcore anti-communists, the rap against McCarthy has always been that he was more interested in grandstanding than in identifying actual infiltrators and building strong, factual cases against them. Herman's book doesn't do a whole lot to counter the charge. "Those who knew McCarthy were constantly discovering to their astonishment how little McCarthy knew about the theory or practice of communism itself," Herman says, and in so saying he makes the senator's supposedly principled anti-communist stance look more like a free-floating xenophobia that just happened to home in on the right target.

Make no mistake: Herman has exhaustively researched McCarthy's life and work, and he dutifully cites the countless mistakes and outrages McCarthy committed. What's bizarre is that none of them seems to have provoked a flicker of indignation in the author. For example, when Herman considers McCarthy's vicious attack on Gen. George Marshall in 1951, he refuses to take the senator's words at anything other than face value. "If Marshall were merely stupid," McCarthy lashed out, "the laws of probability would have dictated that at least some of his decisions would have served this country's interest. ... We have declined so precipitously in relation to the Soviet Union in the last six years, how much swifter may be our fall into disaster with Marshall's policies continuing to guide us?"

Ignoring the obvious implications of McCarthy's statement, Herman complains, "Critics bandied it about that McCarthy had called Marshall a traitor (he had not), a secret Communist (he had not), and even a coward." Is Herman incredibly literal or just naive? It's certainly useful to try to understand, from the senator's point of view, why McCarthy did what he did. But at times Herman simply takes leave of his own judgment. And some of the excuses he offers for McCarthy's conduct are astounding. McCarthy "decided to lump where others took care to split," Herman shrugs. Oh, was that it?

Despite its flaws, Herman's book is fascinating, and it visits a lot of interesting territory: McCarthy's friendship with the Kennedys, his strong political support among Catholic voters, the tactical mistakes that led to his eventual downfall. And Herman makes a strong argument that the grounds on which the Senate censured McCarthy were tenuous at best. But even then, Herman takes his own argument one step too far. He compares McCarthy to the victims of Stalin's show trials, who, after their convictions for nonexistent crimes, were hauled off and executed. For all of Herman's efforts to explain McCarthy's excesses, the resulting book is not at all flattering -- to its author or to its subject.