The journalist and popular historian Richard Rhodes can be surprisingly hypnotic in his writing, given the complex subjects he chooses to write about. His latest book, “Arsenals of Folly: The Making of the Nuclear Arms Race” (Knopf, 383 pages, $28.95), opens with a captivating 20-page account of the Chernobyl nuclear tragedy of April 1986 that showcases the author’s unusual agility in turning phrases on turbines and radionuclides, a gift for which he has already received one Pulitzer Prize.

Mr. Rhodes follows this with an evocative biographical sketch of the early years of Mikhail Gorbachev, the man whom fate — and the Kremlin — had selected to lead the Soviet Union through the terrible crisis. Mr. Gorbachev had a classic background for a reformer: Stalin’s police arrested both of Mr. Gorbachev’s grandfathers in the 1930s, and for five months in 1942 and 1943, the Wehrmacht occupied Mr. Gorbachev’s hometown of Privolnoye. One contemporary of Mr. Gorbachev’s suggested in an interview with Mr. Rhodes that, as an adolescent, Mr. Gorbachev had wanted to be a physicist, but was barred from that profession because in the neurotic Soviet system, even someone who had lived under Nazi occupation as a child was permanently barred from getting a security clearance (unless he were to become General Secretary). Yet it would take Mr. Gorbachev 30 years to turn against the system that had produced such familial tragedy and personal setbacks. Becoming a lawyer and striving apparatchik instead, Mr. Gorbachev demonstrated a work ethic, cleverness, and ambition which powered him to the top of the Soviet state, without revealing to his political patrons — who were all orthodox communists — that within this energetic young man were the seeds of Leninism’s future collapse.

Had the book ended here, it would have been a minor classic, likely only surpassed by William Taubman’s eagerly awaited biography of Mr. Gorbachev. But, instead, Mr. Rhodes set out to write a history of the arms race and why it ended, and here the book comes up short.

Lacking the self-confidence on military matters that drives his description of Chernobyl (and later in the book, his description of the Challenger disaster), Mr. Rhodes disrupts his arms-race narrative with indigestible quotations and analysis from other scholars. The story stumbles and begins to read like a stolid history textbook.

The conventional view of the 40-year superpower arms race combines elements of tragedy and farce, and what one craves from Mr. Rhodes is a meticulous dissection of its causes. Unfortunately, what one gets instead is an unfocused list of forces Mr. Rhodes explores only tentatively: American hubris, the military-industrial complex, the superpower’s mutual misperception, and fear are all cited at one time or other in this book, but none ever authoritatively or convincingly. History is littered with arms races — many of which led to war — but this was the first to involve nuclear weapons, and Mr. Rhodes might well have meditated on its possible uniqueness. What does come through clearly, however, is that however it started, the nuclear buildup was very difficult to stop.

When Mr. Rhodes turns to how the arms race ends, he appears to be on surer ground. Some political partisans may be disappointed in Mr. Rhodes’s convincing portrait of a romantic (President Reagan) and a realist (Mr. Gorbachev) who both wanted to rid the world of nuclear weapons despite the protestations of most of their advisers. But, as Mr. Rhodes concludes, it took two very strong-willed and self-confident men to break the vicious cycle. Neither should receive credit alone.

Mr. Rhodes’s Soviet evidence is not fresh — much of it has been used by scholars for nearly a decade — but he does a fine job of combining it with American memoirs to tell the story of the Reagan-Gorbachev summits. Their Reykjavik, Iceland, meeting in 1986 is even more dramatic in this retelling. Had Mr. Gorbachev not exaggerated the extent to which the Anti-ballistic Missile Treaty actually hindered testing Reagan’s Star Wars fantasy (thus making preserving its restrictions a sacred obligation), he and Reagan might have agreed to a blueprint for a nuclear-free world right then and there.

At times, the book veers into polemics, and one senses in Mr. Rhodes’s historical analysis objections to our current misadventure in Iraq. In particular, Mr. Rhodes singles out neoconservatives for accelerating the arms race and nearly provoking a war with Moscow in the early 1980s. Indeed, obsessed by the growth in the Soviet arsenal of ballistic missiles, neoconservatives such as Richard Perle and Paul Wolfowitz were, Mr. Rhodes argues, on the vanguard of those pushing for a massive American rearmament as well as a confrontational policy toward the Soviets. In reaction, the Soviet gerontocracy concluded that Reagan was willing to launch a nuclear first strike and ordered its inept intelligence community to monitor British blood banks and the patterns of lights on the Pentagon to determine whether an attack was imminent.

But to apportion more blame to one side than another in this period is to ignore the blanket of misperception and deceit that covered both sides throughout the Cold War. Moreover, neoconservatives were hardly the first Americans to overestimate Soviet power. At one time or other traditional conservatives, hawkish Democrats, and moderate Republicans all managed to make the same error. But American ignorance was not solely to blame. It was Soviet policy to foster that overestimation. Nikita Khrushchev, who notoriously (and inaccurately) claimed that Moscow produced missiles like sausages, had set the pattern in the 1950s. Yet our side seemed particularly vulnerable to this fear-mongering. Each time a Soviet leader puffed himself up, Americans got scared, harping on areas where they appeared to be leading instead of soberly assessing the correlation of forces — economic, political, and military.

As late as the 1970s, the Soviets could still hardly feed their people, and their domestic infrastructure was in a shambles. Indeed, less than half of the Soviet countryside had paved roads. It was not fear of America so much as recognition of the weakness of the Soviet system that led Mr. Gorbachev to decide to embark on radical domestic reforms and attempt to end the adversarial relationship with America.

In Reagan, Mr. Gorbachev ultimately found a ready partner. The great man theory of history hasn’t been in vogue since at least Vietnam and Watergate, but Mr. Rhodes reminds us that the peaceful end of the superpower arms race is hard to imagine without the historical luck of having a faded Hollywood actor with a boyish belief in American know-how and an optimistic Soviet lawyer heading their respective countries at the same time.

Mr. Naftali is the author of the forthcoming book in the American Presidents Series, “George H.W. Bush,” published by Times Books.