If even a tenth of what Michael Wolff reports is true, we should really be worried.

Perhaps the most striking episode in Fire and Fury, journalist Michael Wolff’s new book on the first year of the Trump presidency, is its account of the firing of FBI Director James Comey last May.

The sole grounds for the hastily made decision, Wolff reports, was the president’s anger at the rapidly expanding Russia investigation into whether his campaign colluded with Russia. Trump and his family were worried about what the FBI would find out about their finances — and wanted the investigation quashed. The final decision, on May 9, was made with virtually no input from his team; most of the West Wing staff reportedly found out about it from Fox News.

“In presidential annals,” Wolff writes, “the firing of FBI director James Comey may be the most consequential move ever made by a modern president acting entirely on his own.”

Wolff’s description of the Comey firing has gotten less media attention than some of the book’s more inflammatory nuggets, like the idea that Trump didn’t actually expect, or want, to win the 2016 election. But it illustrates perhaps the book’s most important takeaway: The way in which this White House makes major foreign policy and national security decisions is fundamentally broken, and the root cause is Donald Trump himself.

From bombing Syria to the surge in Afghanistan to the standoff with North Korea, Trump behaves largely as he did during the deliberations over whether to fire Comey: ignoring the facts of the situation, making decisions rooted principally in his own personal feelings or connections, then failing to understand the consequences of his actions even after they’ve been taken.

We shouldn’t treat Fire and Fury as gospel; Wolff has a long history of playing loose with the facts and using questionable methods to arrive at his conclusions. Still, the overall portrait jibes with more than a year of other reporting about the Trump presidency.

Given that the president has nearly unfettered power to make major foreign policy decisions, it’s worth taking a serious look at the book’s primary conclusion about Trump as commander in chief.

“If the Trump White House was as unsettling as any in American history,” Wolff writes, “the president’s views of foreign policy and the world at large were among its most random, uninformed, and seemingly capricious aspects.”

The book’s scariest insight is into how Trump makes decisions

Trump, unlike previous presidents, did not come into the White House with any real sense of what he wanted to accomplish in world affairs. “His advisers didn’t know whether he was an isolationist or a militarist, or whether he could distinguish between the two,” Wolff writes.

The result is a foreign policy dominated and shaped by Trump’s personal peccadilloes rather than any kind of ideology or comprehensive worldview. It’s hard to imagine a person less well-suited to making foreign policy decisions than the Trump that appears in Wolff’s book.

The president is practically allergic to facts or being briefed on new situations. This became clear to Trump’s aides during the presidential transition, when he started to receive briefings from US intelligence.

“It was during Trump’s early intelligence briefings, held soon after he captured the nomination, that alarm signals first went off among his new campaign staff,” Wolff writes. “He seemed to lack the ability to take in third-party information.”

Trump also appears deeply reluctant to learn anything more about a given country or conflict. He has come to despise National Security Adviser H.R. McMaster, according to Wolff, because McMaster’s briefings are full of dry information about various global hotspots.

“That guy bores the shit out of me,” the president reportedly declared after meeting the general for the first time, an impression that hasn’t changed over the course of time. Within six weeks, Wolff writes, Trump was threatening to fire McMaster for being too boring.

“The staff’s goal was to keep him off North Korea”

That means that Trump has been unwilling, or unable, to give serious attention to thorny issues like the brutal Syrian civil war. His first major foreign policy crisis, Bashar al-Assad’s deadly April 4 chemical attack in the Syrian town of Khan Sheikhoun, was met with anger from the Oval Office occupant — but not for the reasons one might expect.

“To both [Jared] Kushner and McMaster,” Wolff writes, “it seemed obvious that the president was more annoyed about having to think about the attack than by the attack itself.”

The issue was resolved when Ivanka Trump and White House aide Dina Powell put together a slideshow of images showing children who had been poisoned by the attack. The gruesome images, together with the first daughter’s emotional investment, captured the president’s imagination — leading him to order an attack on a Syrian government airfield.

The Syria episode speaks to the fundamental ways that foreign policy decisions actually get made in the White House, per Wolff: Trump’s emotions and personal connections. Again and again in the book, the president ends up being swayed to one side or the other by personal sentiment.

The decision to fire Comey came after weeks of lobbying from Kushner and Ivanka, who were (in Wolff’s telling) terrified of what the Russia probe might turn up about their family’s finances. Trump’s cozying up to Russia, longtime Trump friend Roger Ailes told Wolff, came from a near-pathological need for Putin’s approval.

The president’s support for Saudi Arabia’s blockade of neighboring Qatar in June, which caused a major rift in the Arab world, seems to stem largely from Jared Kushner’s budding personal friendship with Crown Prince Mohammed bin Sultan, who is virtually certain to be the country’s next king. “Jared’s gotten the Arabs totally on our side,” Trump reportedly crowed in May.

This one-two punch — Trump’s disdain for facts and overriding focus on feelings and personalities — has made the president largely blind to the consequences of his actions. Per Wolff’s account, the president orders major policy changes — bombing Syrian government installations for the first time, withdrawing from the Paris climate change agreement, sending more troops to Afghanistan — with little to no understanding of what the consequences might be.

Take Trump’s vow to meet North Korean provocations with “fire and fury the world has never seen,” the episode from which Wolff’s book takes its name. The statement was improvised during an August press conference that was supposed to focus on opioids. It was, Wolff reports, born equal parts out of Trump’s policy ignorance and personal antagonism to Kim Jong Un:

North Korea had been a heavy-on-detail, short-on-answers problem that he [Trump] believed was the product of lesser minds and weaker resolve — and that he had trouble paying attention to. What’s more, he had increasingly personalized his antagonism with North Korean leader Kim Jong Un, referring to him often with derogatory epithets.

The statement terrified North Korea experts, who were worried about Trump provoking a war with another nuclear-armed power. It also terrified Trump’s staff, according to Wolff, as they spent the next week trying to get the president to stop talking about it — with even the white nationalist rally in Charlottesville, held several days after the “fire and fury” statement, serving as an initially welcome change of subject.

“North Korea, a situation the president had consistently been advised to downplay, now became the central subject of the rest of the week — with most senior staff occupied not so much by the topic itself but by how to respond to the president, who was threatening to ‘blow’ again,” Wolff writes. “Charlottesville was a mere distraction, and indeed, the staff’s goal was to keep him off North Korea.”

All of this serves as a windup to Wolff’s most fundamental, and perhaps scariest, conclusion — that the president is psychologically incapable of understanding the consequences of his actions. When Trump does something, like fire Comey or bomb Syria or threaten North Korea, he does so without any sense of how human beings might be affected by his actions.

“One of Trump’s deficiencies — a constant in the campaign and, so far, in the presidency — was his uncertain grasp of cause and effect,” Wolff writes. “Everyone [in the White House], in his or own way, struggled to express the baldly obvious fact that the president did not know enough, did not know what he didn’t know, did not particularly care and, to boot, was confident if not serene in his unquestioned certitudes.”

The most basic part of rationality, in the way that political scientists and economists define it, is the ability to link means and ends. A rational person identifies the goals they wish to pursue, picks out courses of action that they believe could further said goals, and then pursues them.

If Wolff’s book is even fractionally right — if one-tenth of the specific stories in there are true — then we are dealing with a president who does not meet that standard.