Shortly before midnight on May 1, 2011, President Obama made an unusual, late night television address to the nation to announce that the United States had killed Osama bin Laden. “Tonight, I can report to the American people that the United States has conducted an operation that killed Osama bin Laden, the leader of al Qaeda,” Obama said from the White House East Room. “The death of bin Laden marks the most significant achievement to date in our nation’s effort to defeat al Qaeda.”

Hundreds of college-age young people poured into Lafayette Park, across from the White House, to celebrate the news the next day, on the spring Sunday night.

“Bin Laden’s death suddenly brought into relief the fact that . . . the young Americans celebrating in Lafayette Park had not known peace since they were children,” Spencer Ackerman writes in his powerful new book, Reign of Terror: How the 9/11 Era Destabilized America and Produced Trump. “With bin Laden dead, no alternative outcome in the War on Terror could more plausibly and universally be used to declare that the war was not only concluded but won.”

But Obama, characteristically, restrained himself from any such “mission accomplished” triumphalism. “His death does not mark the end of our effort,” Obama said in his nine-minute announcement. “There’s no doubt that al Qaeda will continue to pursue attacks against us. We must—and we will—remain vigilant at home and abroad.”

In his caution and self-restraint from using the al Qaeda leader’s death to declare an end to the then ten-year-old War on Terror, “Obama squandered the best chance anyone could ever have to end the 9/11 era,” Ackerman writes.

“At the time, his administration instead feared political exposure from overpromising what bin Laden’s death meant,” he writes. “It reflected a political consensus that would have punished Obama for declaring victory during the last, best chance for it that America would have.”

The overreach, excesses, and sheer endlessness of the War on Terror and Forever Wars that the United States pursued in the wake of the September 11, 2001 terrorist attacks not only killed and maimed hundreds of thousands of people in the countries the United States outright invaded or hit with drone strikes, but corroded and weakened laws, norms, political stability, and ultimately democracy at home, Ackerman persuasively argues in Reign of Terror. It exacerbated grievances, manipulated information, normalized violence, and deepened social, economic, and political fissures that Donald Trump exploited to rise to power. It also brought the United States close to the brink of civil unrest, most notably in the January 6, 2021 insurrection/attempted coup by Trump’s supporters seeking to overturn his 2020 election loss, Ackerman asserts. In short, the U.S. response to 9/11 has destabilized the United States in dangerous and lasting ways.

“Long before Trump, the War on Terror revealed how the manipulation of reality and the normalization of atrocity would proceed,” Ackerman writes. “Trump brought aspects of the war home, but fundamentally the war was always home.” He continues:

Experiencing neither peace nor victory for such a sustained period was a volatile condition for millions of people. Trump knew how to explain such humiliations: the War on Terror was an enraging story of insufficient brutality wielded by untrustworthy elites. [ . . . ] A war that never defined its enemy became an opportunity for the so-called MAGA coalition of white Americans to merge their grievances in an atmosphere of righteous emergency. Those options were enabled by how deeply the Forever War had eroded the legal, political, cultural, and economic armor protecting American democracy. [ . . . ]

The War on Terror was by no means the only factor enabling Trump’s rise. But it was a path to power for the others. . . . It is the story . . . that implicates an entire generation of American leaders through either action or acquiescence. Their central blind spot . . . : the belief that the danger they inflicted abroad would not damage their own country. [ . . . ] Of all the endless costs of terrorism, the most important is the least tallied: what fighting it has cost our democracy.

Ackerman, a contributing editor at The Daily Beast, is a longtime national security journalist who has reported for Wired, The Guardian, and The New Republic. He was part of the Guardian team that won the 2014 Pulitzer Prize for Public Service Journalism for Edward Snowden’s revelations about NSA spying. Ackerman has also been awarded the 2013 IRE medal for investigative reporting, and the 2012 National Magazine Award for his Wired series on Islamophobic counterterrorism training at the FBI.

Ackerman’s Reign meticulously, and crushingly, documents the sweep and excesses of the 20-year U.S. Global War on Terror (GWOT), conducted by both Republican and Democratic administrations. He documents the two decades of war, invasion, and occupation of Afghanistan and Iraq, CIA torture, “black site” prisons, Guantanamo, the “extraordinary rendition” of terror suspects to be tortured by autocratic Middle Eastern regimes, and the “signature” drone strikes in Somalia, Yemen, Pakistan. He contrasts NSA communications surveillance and overly broad legal dragnets like the PATRIOT Act with which the United States responded to the 9/11 terror attacks with the narrow, law-enforcement-driven response to the 1994 Oklahoma City bombing conducted by a white U.S. Army veteran, Timothy McVeigh, along with his associate Terry Nichols, with which he opens the book.

The truck bombing of the Alfred P. Murrah Federal Building killed 168 people, including 19 children; it was, at the time, the deadliest attack on U.S. soil in American history. But even so, he writes, no metaphorical “war” was declared. “The need for a successful prosecution after the Murrah bombing . . . ultimately drove a narrow investigative focus onto McVeigh and Nichols,” Ackerman writes. A white supremacist compound in Elohim City, Arkansas, which McVeigh had called two weeks before the bombing, and whose security chief’s card he carried in his wallet, “faced little post-Oklahoma City scrutiny.”

“The response to Oklahoma City was clarifying,” Ackerman writes. “When terrorism was white—when its identity and purpose claimed the same heritage as a substantial amount of the dominant American racial caste—America sympathized with principled objections against unleashing the coercive, punitive, and violent powers of the state. . . . When terrorism was white, the prospect of criminalizing a large swath of Americans was unthinkable. When terrorism was white, the collective American response was to focus the machinery of its wrath anywhere else, sparing white supremacy the expensive violence America pledged against terrorism that was foreign, Muslim, nonwhite.”

Reign ends with the similarly white-dominated insurrection at the U.S. Capitol on January 6, 2021 by Trump supporters, in which to date the FBI has arrested almost 600 people. Though the FBI investigation into the January 6 attack on the Capitol is the largest since 9/11, Senate Republicans, led by Minority leader Mitch McConnell, in May voted against authorizing a bipartisan joint commission to investigate it. House Speaker Nancy Pelosi, in July, announced a Select House committee to conduct the investigation.

Where did a traumatized United States go wrong in its response to 9/11? Ackerman posits that it happened in a series of decisions in the early days of the GWOT, cascading from a failure to specify the enemy as al Qaeda in the Authorization for Use of Military Force (AUMF) drafted in the days after the attacks.

“A basic decision dooming the war from its inception was the result of deliberate indecision,” Ackerman writes. “It concerned the war’s most fundamental question. Who was the enemy?” A draft AUMF prepared by Bush White House attorney Timothy Flanagan and Justice Department lawyer John Yoo “named no specific enemy,” Ackerman writes. “The priority was to give . . . maximum flexibility to the president to wage the war . . . The maximal flexibility Yoo etched into law, combined with Bush’s increasingly messianic depiction of the coming war, meant that the enemy was never going to be just the specific terrorist network responsible for the 9/11 attacks. At the National Cathedral, Bush spoke of ‘the enemies of human freedom’ attacking America.’”

When Congress voted to pass the 2001 AUMF that fall, only one lawmaker, California Democrat Barbara Lee, voted against it, imploring her colleagues to “think through the implications . . . so that this does not spiral out of control,” Ackerman recounts.

“Having abandoned the concept of a war against a specific terrorist organization, Americans would never be able to agree on when it could be won,” Ackerman writes. “If there was a moment the war was conceptually doomed, it was this. Opposing factions within American politics, as well as within the Security State, would never be willing to accept a rival’s definition. That would prevent the war from coming to an agreed-upon end.”

The Bush Administration rejected another opportunity for an early off-ramp from the war on terror in Afghanistan. By early December 2001, a few hundred U.S. Special Operators and the Northern Alliance, the anti-Taliban military front created in the 1990s, had succeeded in overthrowing the Taliban government in Kabul, and were closing in on Kandahar. The Taliban were seeking a negotiated surrender. “The Taliban . . . would surrender and demobilize if their leader, Mullah Mohammed Omar, could remain in Kandahar under some negotiated supervision,” Ackerman writes. But then Defense Secretary Donald Rumsfeld “called a ‘negotiated end’ to the standoff ‘unacceptable to the United States.’”

“As a predictable consequence of the United States’ defining its enemy broadly, its focus on ousting the Taliban and installing a new Afghan regime allowed Osama bin Laden and al-Qaeda to flee,” Ackerman writes. “This cost the United States its first chance to win the War on Terror . . . Rather than concluding the war three months after 9/11, all the United States gained from Tora Bora were prisoners.” Some of the prisoners would be tortured for information.

Ackerman provides a grim, unsparing, if previously known account of the CIA torture of terrorism detainees, the opening of a network of CIA “black sites” to conduct the “enhanced interrogations,” and he traces how the program’s network of tainted associates coopted and compromised political leaders and policymakers even in successor administrations they advised, after Obama formally ended the program on his second day in office.

Indeed, Ackerman turns as much of his righteous anger on Democratic political leaders and Obama in particular for, in Ackerman’s view, accommodating and helping institutionalize the war on terror, endeavoring to make it more legal and sustainable, and less morally objectionable (with Obama’s use of “signature” drone strikes), as he does on its architects and instigators Bush, Cheney, Rumsfeld, the CIA torture contractors and lawyers like John Yoo, who sought to maximize their flexibility to act without legal or other restraints. “Liberal Complicity in the War on Terror,” Chapter 3 is entitled. “Obama, the Security State, and the ‘Sustainable War on Terror,’” Chapter 4.

“Among liberals and leftists, it became a demand to be done in Iraq, one that Democrats exploited to win control of Congress in 2006,” Ackerman writes. “But the Democratic agenda did not include withdrawal from Iraq, let alone abolition of the War on Terror.”

Obama, by virtue of his childhood years in Indonesia, legal scholarship as a constitutional law professor, and lived experience as a Black man descended from a Kenyan economist father and white Kansan mother, “had greater potential than any rival American politician to see the War on Terror through the eyes of those it terrorized. . . . [and] to understand how 9/11 had inflamed white supremacy and how that anger would manifest,” Ackerman writes. But while Obama rejected the Iraq war as a “dumb war,” he categorized the War on Terror as a necessary one—a position Ackerman sees as shortsighted. “He thought a legitimate threat from al-Qaeda [had emerged], requiring a military response,” Obama advisor Ben Rhodes told Ackerman in an interview recounted in the book.

As President, Obama made drone strikes the centerpiece of his counterterrorism strategy, considering them “a responsible, calibrated use of lethal force, a weapon of precision, not one suited to indiscriminate killing,” Ackerman writes. “To guard against their excesses, Obama created a simulacrum of due process . . . known as the disposition matrix.” But the “targeted killing” by CIA drone that Obama was seduced by was not experienced as so clinical or antiseptic from the ground. “At least sixty-six children were among those killed just in the tribal regions of Pakistan during Obama’s presidency,” Ackerman writes. In the meantime, the “drone strikes bound Obama and the Security State. As long as they did, there would never be any legal consequences for the CIA’s torturers and jailers.”

Ackerman is a politically brave and passionate journalist, meticulous reporter, and elegant writer. The introduction to Reign is one of the more powerful pieces about Trump and America I have read in a long time.

My minor quibble about Reign is that it, if anything, it felt perhaps too comprehensive, telling in detail the story of the U.S. response to 9/11 from 2001 through Trump, the Russia investigation, and January 6 insurrection. I felt overwhelmed and burdened at points with so much (often fairly gruesome) information, much of it previously known, and I might have preferred for Ackerman to focus on a few characters or episodes instead of attempting to be so comprehensive. Then again, it is a reasonable choice to have made when deciding to produce a chronicle of this 20-year period in American history, whose details some readers, and surely most future readers and students, may not know.

Ackerman can seem to be advocating at times in Reign for a kind of purity in politics and national security practice that can seem politically unrealistic. When then-presidential candidate John McCain defended Obama as a “good family man” from an audience member who expressed worry that she thought Obama was “an Arab,” Ackerman chastises McCain for not defending Muslims—and for being a hawk and proponent of the War on Terror. “It appeared never to have occurred to McCain that the open-ended war he helped build, against an amorphous entity, would lead her and other Americans to unleash racist fanaticism.” Really? Can most of the racist fanaticism among Americans be attributed to the war on terror? Would it not be there anyway? Anyway, I felt more generously toward what McCain was trying to do with his response to that questioner.

From the vantage point of July 2021, Reign seems to get a lot right, even if it perhaps stretches the case at points. The negotiated surrender the Taliban was willing to take in December 2001 that Rumsfeld rejected looks, in retrospect, like a very good deal, as the United States this summer turns off the lights at Bagram Air Base, 20 years, thousands of lives, and trillions of dollars later. The domestic extremism and white supremacist ideologies that flourished under Trump are now widely acknowledged to be the largest terror threats to the United States. The accommodations to extremism that the Republican Party, still under Trump’s thrall, are making seem to threaten America’s domestic political stability for years to come.

And the battlefield has evolved. Armed drone technology, such as that which the Obama Administration once employed to pursue a more sustainable war on terror, is now in the arsenal of Iranian-backed militias in Iraq, recently targeting U.S. installations there. As the Biden Administration carried out retaliatory strikes against Iranian-backed militia drone facilities to try to establish deterrence in late June, I found myself, partly under Reign’s influence, questioning the continued U.S. presence in Iraq, ostensibly to help Iraq fight ISIS. The question that Ackerman says we failed to ask in 2001, and re-ask in the subsequent two decades of the Forever Wars, still pertains: Who is the enemy?