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?

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.