The Rebellion of Ronald Reagan: A History of the End of the Cold War By James Mann | Viking | 416 pages, $27.95

Depending on your political perspective, Ronald Reagan either had zip to do with the collapse of the Soviet Union or single-handedly tossed it onto history’s ash heap using his unique combination of guile and strength.

Both interpretations are wrong (of course). Or so James Mann concludes in The Rebellion of Ronald Reagan: A History of the End of the Cold War. Mann, the author of the best-selling Rise of the Vulcans, sculpts a more realistic, and ultimately more interesting, figure. Ronald Reagan, it turns out, was the Forrest Gump of Soviet policy.

According to the author, Reagan had essentially no idea what was going on inside the Soviet Union, no sense of Russian history, and a black-and-white view of communism and communists. His major decisions were made either out of political desperation (recall that his presidency was collapsing amid illegal foreign wars and arms deals) or with no vision of what the actual consequence would be. Yet all of the Gipper’s big moves—made against the advice of pretty much everyone, from the intelligence community to the realists to the neocons—were, to use a term his vanquished ideological opponents would understand, correct.

In other words, Mann slays both caricatures of Reagan’s role. For the left, Harry Truman deserves the credit for trouncing the Soviets, having established the policy of containment, while Reagan merely wandered onstage at an opportune moment. The right, meanwhile, hails Reagan for bankrupting the regime by jacking up defense spending while showing Gorbachev the perfect amount of tear-down-this-wall toughness.

Mann effectively demolishes both theories at once. Speculating about a history that never happened is a dubious proposition, but Mann establishes the case that, even contained and economically beaten down, the Soviet system could have limped along for many more decades. Collapse was not inevitable. More importantly, collapse was not predicted by any member of Reagan’s circle, let alone by the president himself. (“The strategy may have existed in [CIA Director William] Casey’s mind, but others in the administration did not see it that way,” Mann writes.) Quite the contrary, in fact. Reagan’s opponents—George Will, Charles Krauthammer, Henry Kissinger, and various other others who discredited themselves during that period—highlighted the Soviets’ strength until the day the Evil Empire disappeared. For them, the arms buildup wasn’t a way to bankrupt this longtime opponent, but the only means to defend America against it.

So if collapse wasn’t inevitable, then isn’t the left wrong to give Truman all the credit? And if Reagan never saw the collapse coming, and never geared his policies to bring about such an event, isn’t the right wrong to anoint him as the ideological dragon slayer? That’s where Gump comes in.

Reagan’s understanding of communists was developed and, importantly, crystallized in a time and place when communism was a serious thing: Hollywood in the 1930s. Reagan was exposed to the far left at its most obnoxious, Stalinist, and sectarian. A New Deal Democrat, he recoiled at what he saw.

The communist, Reagan discerned, “is bound by party discipline to deny that he is a communist so that he can by subversion and stealth impose on an unwilling people the rule of the International Communist Party which is in fact the government of Soviet Russia.” This is a verdict to which Reagan adhered for decades. (In 1960, Mann tells us, Reagan made precisely this pitch in a letter to Hugh Hefner.) He never truly let go of the image he formed in the Thirties, often telling people during his presidency that he knew and understood communists from having rooted them out of the Screen Actors Guild.

When that image conflicted with reality, it confused Reagan. One Soviet official, for instance, had little resemblance to the clowns the president had encountered in Hollywood—which led Reagan to wonder aloud whether the man was really a communist. How could he be?

For Reagan, a communist was a communist, fifty years and half a world of separation be damned. And the president was confident that he could spot a ringer. “Reagan’s personalized version of anticommunism also implied,” Mann writes, “that once a Soviet leader could establish that he was straightforward rather than deceitful and was trying to alter the Soviet system, then Reagan might be willing—more willing, in fact, than Richard Nixon—to give credence to that leader and to try to do business with him.” Thus was made the policy on which billions of lives rested.

Reagan trusted Gorbachev, despite the advice of nearly everyone around him. Trust, but verify. The origin of that durable phrase, Mann relates, is one Suzanne Massie, the most disquieting piece of the Reagan puzzle. Massie was a Russophile who fell in love with the motherland during a Russian language class. She went on to write a ridiculed book on the romanticism of Russian history, and also collaborated with her husband, Robert K. Massie, on the best-selling Nicholas and Alexandra. Mann dedicates a quarter of his book to the bizarre relationship between Massie and Reagan, highlighting how Massie passed along her superficial understanding of Russian culture to a credulous Reagan, who then recycled her tales during major summits. Massie, though, was right: Gorbachev was genuine about trying to open up the system. In listening to her, Reagan had once again done a fairly stupid thing that turned out to be correct. (His top aides, both threatened and bemused by Massie, eventually succeeded in cutting her off from the president.)

Mann devotes another quarter of his book to Reagan’s tear-down-this-wall utterance. He shows that Reagan made this demand against the wishes of his foreign-policy advisers, and largely for the purpose of appearing relevant back home, even as his presidency crumbled. But then again, discerning any motive at all behind Reagan’s actions is difficult, concedes Mann, noting that even Nancy never felt that she fully knew him.

Mann also dedicates a quarter of his book to Reagan’s relationship with Nixon, and another to his summits with Gorbachev. The four-part structure breaks up the narrative arc, as the reader sprints through the Reagan administration four times over. But the form does serve the purpose of building a solid argument, which will be tough to knock down.

Now, if Reagan was Gump in this drama, then Mikhail Gorbachev was Jenny: the smart, well-meaning lefty whose best efforts inevitably ended in disaster. (Forget the Forrest-Jenny romance; the analogy falls apart there.) Gorbachev’s strategy to open the Soviet system in order to strengthen it failed. And it would have failed, Mann argues, whether Reagan had hiked defense spending or not. The Soviet economy was in the tank, suffering from structural weaknesses that sapped the strength of the central government. Gorbachev’s only real ace in the hole was his cooperative relationship with Reagan.

Soviet conservatives, who battled Gorbachev’s reform efforts, lost their greatest talking point when the American president stopped acting like an enemy. Yet Reagan was able to strengthen Gorbachev just enough so that he could carry out his reforms, but not enough to keep him in power. And in the end, Reagan’s seemingly naïve view of the communist character turned out right. He always believed that if he could simply show Gorbachev the wealth the American system created, he’d be moved to change his mind. Gorbachev stuck to his ideological guns. But his opponents in the elite sphere of the Soviet government did not. They saw what riches lay before them for the taking. When Gorbachev, with Reagan’s help, opened the door, they walked in and took them. And then slammed the door shut again.

Ryan Grim is a congressional correspondent for the Huffington Post. He is a former staff reporter with Politico.com and Washington City Paper and is the author of the forthcoming book, This Is Your Country On Drugs.