The first female president of the United States faces her first major international conflict: Seeking to consolidate the Slavic nations of Eastern Europe, Russia has seized the three Baltic states—Latvia, Lithuania, Estonia—all members of NATO. That requires a response beyond just a caustic tweet or sharply worded press release. For the first time since the Cuban missile crisis, there is serious talk of nuclear war.

This is the basis of 2017 War with Russia, the unsettling new book by General Sir Richard Shirreff, who retired in 2014 as NATO’s deputy supreme commander of Europe, as well as its highest-ranking British officer. Although 2017 is technically a novel, this “future history” is really just a war game on the printed page, its preoccupations much closer to those of von Clausewitz and Churchill than those of Woolf or Wordsworth. Shirreff’s book is subtitled “An urgent warning from senior military command,” and he makes plain in his introduction that the novel’s primary intention is to convey the urgency of containing Russian President Vladimir Putin. He likens today’s Mother Russia to Germany in the late 1930s, when it seized the Sudetenland in brazen contravention of established borders. War-weary Europe let the matter slide, hoping that talk of a Thousand Year Reich was just bluster.

“I’m worried, very worried, that we’re sleepwalking into something absolutely catastrophic,” Shirreff tells me, speaking on a Friday evening from his home in Hampshire, in the bucolic country outside of London. A graduate of Oxford who served in the British army, with deployments in the Middle East and the Balkans, he is not a natural writer, so the judgment of the Financial Times—that this is a “literary disaster”—is not as stinging as it might otherwise be, since that same review praised Shirreff’s grim geopolitical vision as one of “profound importance.” 2017 is an unabashedly didactic work, a real-life warning with the bold-faced names changed.

The novel opens with the Russians staging an attack on a school in Donetsk, the breakaway region of the Ukraine controlled by pro-Kremlin separatists since 2014. Close to 100 children are killed, and Ukrainian forces are blamed, thus giving the Russians the perfect pretext for further aggression. Russia used a similar ploy—the bombing of several apartment buildings in Moscow in 1999—to begin the first Chechen War. But let’s not give Putin too much credit: He likely learned the tactic from Hitler, who was probably behind the Reichstag fire of 1933, which allowed the Nazis to eliminate political opponents before moving on to more grandiose aims.

The Ukrainian operation is only the start. Putin—his identity is very lightly disguised by Shirreff, as is that of Hillary Clinton, though he says she wasn’t necessarily his model for the American president—has his eyes on the Baltics, which Russia has long regarded as its birthright. The Kremlin is bolstered by a conviction that Western Europe and the United States will do anything to avoid the use of force. “The West may have great economic capability, but they think only of social welfare,” one Kremlin adviser says in 2017. “They have forgotten to stand up for themselves.”

When I spoke to Shirreff, he lamented the ease with which Russia invaded both Georgia (2008) and the Ukraine (2014). “That was a slick, very professionally executed operation,” he says of the conquest of Crimea, one that Putin may well try to replicate in the Baltics, given how little genuine resistance he encountered from the West two years ago. “Russia despises weakness and respects strength,” Shirreff tells me. It’s no accident that, every few months, the nation goes agog over images of Putin, stolid and shirtless, wrestling a bear or cuddling with a Siberian tiger.

Until a few weeks ago, most American readers of 2017 would not have thought twice about the preface by James Stavridis, the now-retired American admiral who served as the NATO Supreme Commander of Europe. But in July, media outlets reported that Stavridis was being seriously considered by Clinton as her vice presidential candidate. If he is to serve as an advisory role in her presidency, his view of Russia would be useful. And as presented here, that view is utterly unambiguous: “Of all the challenges America faces on the geopolitical scene in the second decade of the 21st century, the most dangerous is the resurgence of Russia under President Putin.” When Mitt Romney said as much during his 2012 presidential bid, he was mocked for stoking anachronistic Cold War fears. “The 1980s are now calling to ask for their foreign policy back,” President Obama said glibly of Romney’s warning.

But the 1980s actually saw the rise of nuclear disarmament, as well as a broader thawing of Russo-American relations. This moment, the one we live in, feels closer to the 1960s, with American missile defense shields rising in the former Soviet bloc countries of Romania and Poland, as well as military exercises that seem like preparations for the real deal. Annoyed by such exercises in Eastern Europe conducted by NATO, a Kremlin senior official put the matter as bluntly as one of Shirreff’s characters: “If NATO initiates an encroachment—against a nuclear power like ourselves—it will be punished.” This kind of bluster could easily have come from the Kremlin of Khrushchev, as both sides prepared for mutual assured destruction.

I spoke to Shirreff just days after hackers universally believed to be associated with the Kremlin broke into the servers of the Democratic National Committee, a breach the director of national intelligence called “a version of war” (though he also tried to temper suggestions that Russia was at fault). Donald Trump openly encouraged further such incursions, as long they helped his quest for the White House.

When I first spoke with Shirreff, he declined to comment on Trump’s overtures to the Kremlin, but by the next morning, he’d changed his mind and sent me an email that said, in part: “What could suit Putin better than to embarrass the Democrats and so propel into the White House a candidate who has undermined NATO’s doctrine of collective defence by raising questions over America’s willingness to support an ally if attacked?” He was referring to Trump’s suggestion that the United States would not come to the aid of NATO allies who hadn’t made the requisite defense expenditures.

It is far more likely, according to most projections, that the next president will be Clinton, a longtime foe of Putin who has shown a willingness to use American force abroad. Shirreff believes that nuclear war with Russia is a possibility: Kaliningrad, a region of Russia that borders the Baltic States, now serves as a growing repository for both conventional and nuclear weapons, including Iskander missile systems that have nuclear capability and a range of 300 miles. These could be fired at the West—and will be, if Putin finds Russia’s borders with Europe threatened. Of course, if he invades the Baltics, such a counterattack would be required by the “collective defense” doctrine of the North Atlantic Treaty, known as Article 5. “If NATO goes to war with Russia,” Shirreff says, “that means nuclear war.”

His solution is paradoxical: a show of strength and unity by NATO that would discourage any offensive moves on Russia’s part, so that NATO’s strength would never be tested. In other words, frighten Russia into acceptable, rational-actor behavior. Shirreff adds that Trump is “absolutely right” about many European nations failing to meet their financial obligations to NATO, even if the failed casino magnate couched his criticism in undue threats about abandoning treaty commitments. “Europe needs to step up to the mark,” Shirreff says.

He also says the West needs to commit once more to a dialogue w