Powell’s friends in America tend to briefly note, in the soft glaze of his own regret, the most consequential act of his life. On February 5, 2003, Powell made a 76-minute speech to the United Nations Security Council in which he argued the Bush administration’s case for invading Iraq. He insisted that Iraq’s leader, Saddam Hussein, was overseeing a secret program to make weapons of mass destruction. Powell brandished satellite photos of what he confidently said were decontamination trucks, aluminum tubes, and other WMD paraphernalia. He even held up a vial that he said could contain anthrax.

There was, of course, a big problem with all of his assertions: They were lies. The intelligence behind his speech was the opposite of emphatic — it was false, manipulated, and fabricated. The trucks were just trucks. The tubes were just tubes. There was no anthrax. There was, more fundamentally, no reason to invade Iraq. Nonetheless, thanks to Powell’s presentation, the Bush administration went ahead with its plans, and in the ensuing catastrophe, at least several hundred thousand Iraqis lost their lives, as well as more than 4,000 U.S. soldiers.

There is no shortage of senior officials in the Bush era who had a higher quotient of intentional malignance than Powell. We know their names well: Dick Cheney, Donald Rumsfeld, Condoleezza Rice, George Tenet, Paul Wolfowitz, and, of course, Bush himself. But Powell was unique in a way that does not flatter his legacy: He was perhaps the only public figure who could have stopped the White House from going ahead with its lunatic invasion, and he failed to do so. In a lengthy article published last year, writer Robert Draper traced the what-if of Powell, the most popular member of Bush’s post-9/11 Cabinet, telling the truth when it mattered:

What if that same voice that publicly proclaimed the necessity of invading Iraq had instead told Bush privately that it was not merely an invitation to unintended consequences but a mistake, as he personally believed it to be? What if he said no to Bush when he asked him to speak before the U.N.? Powell would almost certainly have been obligated to resign, and many if not all of his top staff members involved in the Iraq issue would also have quit.

Dominoes would have continued to fall. The British foreign secretary, Jack Straw, would have almost certainly followed Powell’s example, which meant that the crucial British support for the invasion would have cratered. In the U.S., Draper noted, “Doubters in the upper ranks of the American military — there were several — would have been empowered to speak out; intelligence would have been reexamined; Democrats, now liberated from the political pressures of the midterm election, would most likely have joined the chorus.”

That was the path not taken, because Powell would not stand up to Bush.

“I didn’t have any choice,” Powell told Draper feebly. “What choice did I have? He’s the president.”

The ironic twist of not just Powell’s career but also the careers of so many American generals is that they abjectly lacked, when the moment called for it, the one thing that soldiers are supposed to possess in abundance: courage. The history of the wars in Iraq and Afghanistan is filled with U.S. generals who were lauded as heroes but lacked the guts or honesty to stand up to the whims and dictates of their superiors. Millions of people have been killed and injured on their failed watch since 9/11.