History books can be historic events, making history by ending important arguments. They can make it impossible for any intellectually honest person to assert certain propositions that once enjoyed considerable currency among people purporting to care about evidence.

The author of one such book, Robert Conquest, an Englishman who spent many years at Stanford’s Hoover Institution, has died at 98, having outlived the Soviet Union that he helped to kill with information. Historian, poet, journalist and indefatigable controversialist, Conquest was born when Soviet Russia was, in 1917, and in early adulthood he was a communist. Then, combining a convert’s zeal and a scholar’s meticulousness, he demolished the doctrine that the Soviet regime was a recognizable variant of the European experience and destined to “convergence” toward Western norms.

Books do not win wars, hot or cold, but they can help to sustain the will to win protracted conflict, producing clarity about the nature of an evil adversary. In 1968, five years before the first volume of Aleksandr Solzhenitsyn’s “The Gulag Archipelago” was published in the West, Conquest published “The Great Terror,” a history of Josef Stalin’s purges during the 1930s. In one episode, which could have come from Arthur Koestler’s classic 1941 novel “Darkness at Noon,” Conquest recounted a conversation between Stalin and an aide named Mironov, who was failing to extract a confession — to a political crime — from a prisoner named Kamenev:

“‘Do you know how much our state weighs, with all the factories, machines, the army, with all the armaments and the navy?’

"Mironov and all those present looked at Stalin with surprise.

”‘Think it over and tell me,’ demanded Stalin. Mironov smiled, believing that Stalin was getting ready to crack a joke. But Stalin did not intend to jest. … ‘I’m asking you, how much does all that weigh?’ he insisted.

“Mironov was confused. He waited, still hoping Stalin would turn everything into a joke. … Mironov … said in an irresolute voice, ‘Nobody can know that. … It is in the realm of astronomical figures.’

”‘Well, and can one man withstand the pressure of that astronomical weight?’ asked Stalin sternly.

“‘No,’ answered Mironov.

”‘Now then, don’t tell me any more that Kamenev, or this or that prisoner, is able to withstand that pressure. Don’t come to report to me,’ said Stalin to Mironov, ‘until you have in this briefcase the confession of Kamenev!’“

In 1968, Conquest’s mountain of evidence of the diabolical dynamics of the Soviet regime disquieted those, and they were legion, who suggested a moral equivalence between the main adversaries in the Cold War, which, they argued, had been precipitated by U.S. actions.

In 1986, Conquest published "The Harvest of Sorrow: Soviet Collectivization and the Terror-Famine,” his unsparing account of the deliberate starvation of Ukraine in 1932 and 1933, which killed, at a minimum, 7 million people, more than half of them children. At one point, more Ukrainians were dying each day than Jews were to be murdered at Auschwitz at the peak of extermination in the spring of 1944.

Conquest’s work is pertinent to understanding Vladimir Putin’s Russia. Conquest’s thesis was not that Soviet leaders studied Lenin’s turgid writings but that they were thoroughly marinated in the morals of the regime Lenin founded and that produced the repression machinery that produced Putin.

Conquest’s death follows that in June of another servant of intellectual integrity, Allen Weinstein. In 1978, the 30-year war against the truth waged by Alger Hiss, the U.S. diplomat and traitor, was ended when Weinstein published “Perjury: The Hiss-Chambers Case.” This definitively dismantled the edifice of mendacity that Hiss and his supporters had erected to assert the injustice of his imprisonment for perjury — for lying about his espionage for the Soviets. Hiss still has a ragtag remnant of defenders, historical illiterates who are disproportionately academics. They often are the last to learn things because they have gone to earth in the groves of academe in order to live in an alternative reality.

Conquest lived to see a current U.S. presidential candidate, a senator, who had chosen, surely as an ideological gesture, to spend his honeymoon in the Soviet Union in 1988. Gulags still functioned, probably including some of the “cold Auschwitzes” in Siberia, described in Conquest’s “Kolyma.” The honeymooner did not mind that in 1988 political prisoners were — as may still be the case — being tortured in psychiatric “hospitals.” Thanks to the unblinking honesty of people like Conquest, the Soviet Union now is such a receding memory that Bernie Sanders’ moral obtuseness — the obverse of Conquest’s character — is considered an amusing eccentricity.

© 2015, Washington Post Writers Group