Restrictive new laws silenced democratic debate, including remembrance of the victims of Soviet-era crimes. Memorial associations were condemned as alien invaders. “Russia’s own past became a foreign threat”—but it all started with the August 2012 law outlawing advocacy of gay rights.

Yet the most crucial turn to a new kind of politics—one now agonizingly familiar to Americans—arrived with the Russian invasion of Crimea in February 2014. Even as Russian troops in Russian uniforms seized the peninsula, Putin denied anything was happening at all. Anyone could buy a uniform in a military surplus store. Russia was the victim, not the aggressor. “The war was not taking place; but were it taking place, America was to be blamed.”

Snyder identifies a new style of rhetoric: implausible deniability. “According to Russian propaganda, Ukrainian society was full of nationalists but not a nation; the Ukrainian state was repressive but did not exist; Russians were forced to speak Ukrainian though there was no such language.”

Russian TV told wild lies. It invented a fake atrocity story of a child crucified by Ukrainian neo-Nazis—while blaming upon Ukrainians the actual atrocity of the shooting down of a Malaysian civilian airliner by a Russian ground-to-air missile.

But Russia’s most important weapon in its war on factuality was less old-fashioned official mendacity than the creation of an alternative reality (or more exactly, many contradictory alternatives, all of them Putin-serving). “Russia generated tropes targeted at what cyberwar professionals called ‘susceptibilities’: what people seem likely to believe given their utterances and behavior. It was possible to claim that Ukraine was a Jewish construction (for one audience) and also that Ukraine was a facist construction (for another audience),” Snyder writes.

In 2014, Facebook was not yet a decade old; Twitter younger even than that. As a state weak in conventional means of power, Russia early identified the potential to weaponize these new tools against stronger foes. “The Russian economy did not have to produce anything of material value, and did not. Russian politicians had to use technologies created by others to alter mental states, and did.”

Perhaps this campaign might have been defeated by strong responses by Western governments and truthful reporting by Western media. Indeed, Snyder dedicates his book to reporters, “the heroes of our time.” But alongside those heroes were others working for other ends. Snyder quotes his own warning from the Ukraine war: “Here is going to be there.” Americans and Europeans were left unready to face the new Russian techniques “because writers they trusted were not analysts of, but rather participants in, the Russian campaign to undermine factuality.” Snyder cites repeated examples of journalists in prominent platforms, trusted by left-of-center readerships, whose reporting seemed to support Russian claims that Ukraine had become a romper room for neo-Nazis—or alternatively to “the green flag of jihad.” Many of these reports cited second- and third-hand sources, some of whom disappeared untraceably after depositing their testimonies on Facebook. Hard-left and alt-right social-media trolls then tidied up after the reporters, belittling claims that the original sources were disinformation. Of one such troll, Snyder quips—in an apothegm that applies sadly widely—“he did not see the Russian intervention because he was the Russian intervention.”