What would happen if a nuclear power station in California were hit by a nuclear weapon launched by North Korea? Many people within a nine-mile radius would be vaporised or burnt to death, and the reactor would melt down, causing a lethal rain of radioactive uranium shards. And, in this imagined chain of events, that’s just the beginning. Another missile heads towards Washington DC. Images of a mushroom cloud cause panic on social media. Then again, as the Pulitzer-finalist journalist Annie Jacobsen observes in this book, the destruction of the Californian plant would also have the effect of permanently taking the social network formerly known as Twitter offline. So it’s not all bad news.

The June 1957 'Priscilla' test in Nye County, Nevada

Nuclear War: A Scenario is a breathless, minute-by-minute description of one way in which, thanks to apparent North Korean paranoia, a global thermonuclear war could suddenly erupt. It’s based on hundreds of interviews with many retired security officials and more-or-less declassified information in the public domain. What it captures brilliantly is the emotional chaos into which leaders would be plunged in such a situation: Jacobsen paints a disturbingly persuasive picture of a panicking, dithering American president, given only a few minutes to decide whether to retaliate by nuking Pyongyang before the first incoming missile even hits – in other words, to obey the “Launch on Warning” doctrine current in the US – while being shouted at by an entourage that ranges from the ­cautious to the insanely hawkish. These are scenes straight out of Dr Strangelove.

Jacobsen’s book also details the mad logic of escalating retaliation that takes hold, and the large contri­bu­tion to disaster made by ­unreli­able technology. American missile-defence simply doesn’t work half the time. The president orders a massive strike on North Korea (before another Korean nuke hits Washington DC and downs his fleeing helicopter), but the trajectory of those nukes will take them over Russia to hit the target. The Russ­ian missile-alert system is err­atic and they think there are twice as many coming towards them over the Arctic Circle. They demand to speak to the president on the phone, but the president is nowhere to be found. (He’s bleeding in a forest.)

North Korea then detonates a nuke in space above the US, causing a massive electromagnetic pulse that destroys the electricity grid, and all infrastructure goes down. Finally, out of injured pride – having received no call back – the Russians launch their own nukes before the American ones pass them on their way to Pyongyang. Less than an hour after the first explosion at the Californian power plant, Russian bombs destroy the capitals of Eur­ope; 14 minutes later, 1,000 Russ­ian missiles strike targets in America. Half a billion people die. Nuclear winter looms. Soon, no food will grow in the northern hemisphere.

Throughout the book, Jacobsen is rather facetiously sceptical about the idea of deterrence, which is how all nuclear powers justify their stockpiles of such weapons. It ought to be acknowledged, however, that because of deterrence no nuclear war has broken out in nearly 80 years, and that the rogue states who seek to acquire nuclear weapons, from North Korea to Iran, do so precisely because they know that being so armed will deter forceful interference in their affairs by hostile superpowers. To allow this is consistent with knowing, as Jacobsen writes, that “nuclear war is insane. Every person I interviewed for this book knows this. Every person.”

To contemplate insanity, perhaps, is challenging for one’s prose. In terms of style, Nuclear War appears to have been written for those who find the novels of Dan Brown too sophisticated. Pulp-thrillerish one-sentence paragraphs abound. Of historical con­tin­gency plans for nuclear war, the author writes, unnecessarily: “The so-called unthinkable, and yet, most definitely, not unrehearsed.” Nuclear-armed sub­mar­ines, which can empty their tubes of intercontinental ballistic missiles in a minute, are called “the handmaidens of the apocalypse” every time they’re mentioned. Words are sometimes jumbled or redundant, or both. Almost everything is “dreaded” or called “Doomsday”.

As a literary work, then, Nuclear War is inferior to the brilliant docu-novel by the arms-control expert Jeffrey Lewis, The 2020 Commission Report on the North Korean Nuclear Attacks Against the United States (2018), which takes the forensically persuasive form of an official inquiry into a nuclear exchange between Kim Jong-un and Donald Trump. But Jacobsen’s book provides a more accessible and deeper compendium of the unsettling facts about nuclear history, planning, and devastation, and her addition of Putin and his henchmen into the mix – although what China is doing during this apocalyptic hour is, oddly, never mentioned – makes for a snowballing scenario that leads to a much worse ending, one in which no one is even left to write an official report. Come the US presidential election in November, both books might come to seem uncomfortably of the moment again.