There is a question about the American-led invasion of Iraq that, 20 years later, remains a matter of deep uncertainty and debate among historians, political scientists and even officials who helped set the war in motion.
It’s not the war’s toll in American military deaths (about 4,600) or Iraqi lives (estimates generally fall around 300,000 or more killed directly by fighting). Nor the financial cost to the United States ($815 billion, not counting indirect costs like lost productivity).
It’s not even the war’s consequences, which are broadly understood to include, at a minimum, plunging Iraq into civil war, giving rise to a new generation of jihadism and, for a time, chastening American interventionism.
Rather, it’s question that would seem to be far simpler: Why did the United States invade at all?
Was it really, as the George W. Bush administration claimed in the war’s run-up, to neutralize an active Iraqi arsenal of weapons of mass destruction that turned out to not exist?
Was it over, as the administration heavily implied, suspicions that Saddam Hussein, Iraq’s leader, had been involved in the attacks of Sept. 11, 2001, which also proved false?
Was it to liberate Iraqis from Mr. Hussein’s rule and bring democracy to the Middle East, as the administration would later claim?
Oil? Faulty intelligence? Geopolitical gain? Simple overconfidence? Popular desire for a war, any war, to reclaim national pride? Or, as in conflicts like World War I, mutual miscommunication that sent distrustful states bumbling into conflict?
“I will go to my grave not knowing that. I can’t answer it,” Richard Haass, a senior State Department official at the time of the invasion, said in 2004 when asked why it had happened.
It’s not that there’s some still-missing puzzle piece or state secret. Quite the opposite: As time has passed, journalistic investigations and insider testimonies have explored nearly every facet of the invasion.
Rather, the challenge is determining which motives, stated or unstated, most mattered. What strategic, ideological or even bureaucratic interests brought the war’s architects together? And did the march to war — or was it a drift? — begin with Sept. 11 or, as some historians now argue, several years earlier?
The world may never get a definitive answer. The causes of World War I remain debated over a century later, as do those of the American interventions in Vietnam and Korea.
This speaks to an uncomfortable truth: History-changing decisions are often made through processes and rationales so convoluted that even the people involved might not know exactly how they happened. Hundreds of thousands might die, an entire country plunged into violence, without anyone able to quite say why.
Still, the last 20 years have brought us closer to, if not a simple answer, then a set of overlapping theories. And that inquiry has often taken place with an eye on the future as much as the past.
“If you want to prevent this from happening again,” said Elizabeth Saunders, a Georgetown University scholar, “you need to get the diagnosis right.”
Searching for Motive
One question has drawn particular scrutiny: Did the administration sincerely believe its rationale for war, or engineer it as a pretense?
Insider accounts consistently portray the administration as playing down or rejecting mountains of intelligence contradicting its claims, instead cherry-picking circumstantial evidence for its case.
That began in the hours after the Sept. 11 attacks, with Paul Wolfowitz, the deputy defense secretary, pressing subordinates for proof of his suspicion that Mr. Hussein had been involved. Four days later, at a Camp David meeting, Mr. Wolfowitz and others argued that Mr. Hussein was probably responsible, urging Mr. Bush to consider military action.
“I believe Iraq was involved,” Mr. Bush told his national security team two days later, adding that he did not yet have the evidence to act, according to interviews conducted by the journalist Bob Woodward.
Soon after, officials began making this case publicly.
Tellingly, when evidence proved elusive, the administration did not slow its drive, but rather changed its rationale.Officials claimed that Mr. Hussein possessed, or would soon possess, nuclear, chemical and biological weapons that he might intend to use against the United States. Those claims were carried, and amplified, by America’s major media outlets.
We now know officials often misrepresented what they had. But meeting notes and other accounts do not show them as plotting to sell a weapons threat that they knew was fictitious, nor as having been misled by faulty intelligence.
Rather, the record suggests something more banal: A critical mass of senior officials all came to the table wanting to topple Mr. Hussein for their own reasons, and then talked one another into believing the most readily available justification.
“The truth,” Mr. Wolfowitz told Vanity Fair in 2003, “is that for reasons that have a lot to do with the U.S. government bureaucracy, we settled on the one issue that everyone could agree on, which was weapons of mass destruction, as the core reason.”
Dr. Saunders, the Georgetown scholar, called the result “a log roll.”
“Each individual had their reasons and their biases,” she said. “And the absence of experience at the presidential level enabled those biases.”
The weapons claims, in this view, reflected something arguably more pernicious than a miscalculation or a lie: an assumption that went effectively untested because too many senior officials wanted it to be true.
In that context, the move to invade seems to have been an accumulation of individual biases and institutional breakdowns that created a momentum all its own.
“It was an accretion, a tipping point,” Mr. Haass, the former official, later told the journalist George Packer. “A decision was not made. A decision happened, and you can’t say when or how.”
Searching for a Cause
Yet this does not explain why those officials all suddenly converged on toppling Mr. Hussein.
One school of thought focuses on the impersonal forces of international relations, which may have sent the two countries careening toward a war that served neither’s interests.
One such reading cites the cold logic of game theory, with distrustful adversaries locked in escalating threats and bluffs that began in the conflicts of the 1990s.
Mr. Hussein, in this view, overstated his willingness to fight and concealed the paltry state of his weapons programs to appear strong at home and deter the Americans, who had attacked in 1998. But Washington believed him. Meanwhile, Mr. Bush’s threats were perhaps misread in Baghdad as a bluff. Several rounds later, they were at war.
Still, miscommunication cannot explain the final run-up, when Baghdad allowed weapons inspectors total access and Washington established the sincerity of its invasion threats.
Others suggest that after Sept. 11, “the United States felt the need to regain status and establish itself as an aggressive global power,” the scholar Ahsan Butt has written. This was rooted in a calculation that America’s greatest source of strength was global perceptions of the country as unchallengeable.
“If there was a hidden reason, the one I heard most was that we needed to change the geopolitical momentum after Sept. 11,” Mr. Haass has said of internal deliberations. “People wanted to show that we can dish it out as well as take it. We’re not a pitiful helpless giant.”
Scholars now largely doubt another, once-prevalent theory: that Washington invaded to control Iraq’s vast oil resources. One book-length study concluded that while Iraq’s oil heightened its importance to Washington, the invasion was “not a classic resource war, in the sense that the United States did not seize oil reserves for profit and control.”
Searching for a Reason
There is growing focus on the second school of thought for why American policymakers moved to war.
“Scholars of the Iraq War should shift their attention from the thoroughly examined 18 months between 9/11 and the March 2003 invasion to the pivotal decade of the 1990s, when Iraq became a major political and foreign policy issue in the United States,” Joseph Stieb, a U.S. Naval War College historian, wrote for the website War on the Rocks.
It is in the 1990s, Dr. Stieb argued, where historians would find “the intellectual, political and cultural scaffolding of the beliefs that motivated the 2003 Iraq War.”
After the Cold War’s end, a small circle of policymakers and academics calling themselves neoconservatives argued that the United States, rather than drawing down, should wield its now mostly unchallenged power to enforce an era of “global benevolent hegemony.”
The United States’ military dominance, rooted in American ideals, would smash the last vestiges of despotism from the world, allowing democracy and peace to flourish. Any resistance, they warned, however small or remote, was a threat to the entire American-led order.
After years as intellectual insurgents within the Republican Party, the neoconservatives were suddenly elevated to an influential policy board in 1998. Newt Gingrich, who was then speaker of the House, had turned to them after the party’s 1996 election losses, believing that new ideas would attract voters.
Members included Mr. Wolfowitz as well as Dick Cheney, Donald Rumsfeld and Condoleezza Rice, who would become Mr. Bush’s vice president, defense secretary and secretary of state.
Neoconservatives also formed Project for the New American Century, a think tank, to act as the voice for the movement, which now spoke for the Republican Party. As one of its first acts, the group issued an open letter to the Clinton administration warning, “We may soon face a threat in the Middle East more serious than any we have known since the end of the Cold War.”
It urged President Bill Clinton to “aim, above all, at the removal of Saddam Hussein’s regime from power.”
Small and relatively poor, Iraq would seem an unusual choice as a new national rival, but neoconservatives’ view required an adversary to explain why the world had not yet rallied behind American leadership. In the late 1990s, a time of nearly unrivaled American dominance, there were simply few candidates.
Iraq also appealed for another reason. Mr. Hussein had ejected international weapons inspectors, which was seen in Washington as a humiliating policy failure for Mr. Clinton.
When the American leader was weakened by scandal later that year, congressional Republicans pounced, passing the Iraq Liberation Act, which declared toppling Mr. Hussein an official U.S. policy. Mr. Clinton signed the bill, and although he resisted its call for removing Mr. Hussein, he later used it as legal justification for airstrikes on Iraq.
With war no longer entirely a hypothetical, neoconservatives portrayed Iraq as a proving ground for their larger mission. A pro-American democracy would, they argued, naturally arise in Mr. Hussein’s place, and other countries in the Middle East would quickly follow, transforming the region.
When Mr. Bush became president two years later, he filled out his administration with neoconservative luminaries who had led that charge.
“The longer I’ve studied this,” Madison Schramm, a University of Toronto scholar, said of the Iraq invasion, “the more I see it as a continuity in policy” dating to the 1990s.
Few scholars argue that Mr. Bush’s team came into office plotting to invade Iraq and then seized on Sept. 11 as an excuse. Rather, one growing view is that in the shock of the attack, many officials, grasping for an explanation, saw confirmation of the neoconservative view that seemed to provide one.
Mr. Hussein was the heart of the Middle East’s political and social rot, they said, and only purifying American power could solve the region’s ills.
Still, the competing theories tend to share a common baseline: that a mix of ideological convictions, psychological biases, process breakdowns and misaligned diplomatic signals led to an invasion that did little to serve the goals that its architects believed they were advancing.
And that may not be so unusual. A year into Russia’s invasion of Ukraine, analysts are still trying to peer into the mind of President Vladimir V. Putin of Russia to understand why he did it so that they might craft a way to turn him back.
No matter how much we know about the facts of the 2003 invasion, Dr. Saunders said, “some of it will remain fundamentally unknowable.”