Throughout the last third of George W. Bush’s presidency, opinion leaders were obsessed with the question of mistakes. Among most members of the press and among Democratic officeholders — even, or perhaps especially, those who voted to approve the Iraq War — the appetite was strong to hold President Bush in a half nelson until he admitted that the war had been a terrible mistake. When Jeb Bush entered the presidential race, he was quickly charged with fraternal guilt in the matter.

It isn’t unfair to ask policymakers to reflect on their misjudgments — or their predecessors’ — but there is a studied lack of interest in mistakes made by this president.

Republicans have all been asked: “Knowing what we know now, was it a mistake to go into Iraq?” That’s an unserious way of putting the question. No decision is made with the benefit of hindsight.

Perhaps President Bush was wrong to topple Saddam Hussein. I don’t think the verdict is clear. But excepting the original decision to invade, Bush’s errors were recognized and corrected before he left office. Barack Obama’s mistakes, by contrast, have been far more consequential and far more threatening to world order and American security than George W. Bush’s were. There is zero evidence that Obama even recognizes them, far less that he plans to correct them. Nor have the Democratic candidates been asked about them.

The Iraq that President Obama inherited was, by his own reckoning, “sovereign, stable and self-reliant.” Obama used those words when announcing the complete American withdrawal of forces in 2011. He went on to say that Iraq had “a representative government that was elected by its people.”

Not quite. There was a free and fair election in 2010, in which a moderate Sunni alliance led by a secular Shiite received a plurality. But the loser, Nouri al-Maliki, hijacked the election and took power. President Obama looked the other way, perhaps because he wasn’t interested in Iraq’s fate, or more likely because Maliki was Tehran’s man, and President Obama has consistently leaned toward Iran’s interests in the Middle East.

Obama stuck to his determination to withdraw every American from Iraq, thereby radically diminishing U.S. influence in the most explosive part of the globe.

What came next was even worse. Acquiescing in the stolen election, Obama then backed Maliki even as Maliki brutalized Iraq’s Sunni minority. Jobs and salaries promised to Sunni groups who had cooperated against al-Qaida when Bush was in office were never paid by Maliki. Dozens of Sunni leaders, many of them moderates, were driven from office; others were arrested, and some, including the staff of Iraq’s vice president, were tortured. Shiite militias were permitted free reign in Sunni regions of Iraq, committing rapes, murders and arson. As one Sunni activist told The New York Times, he didn’t like Islamic State, but the group “will be the only Sunni militia who can fight against the Shiites.”

The Sunnis are key to defeating Islamic State. They cooperated with the U.S. under President Bush. It was called the Sunni Awakening. Now, they can read the signs: America is siding with the Shiites in Iraq, Syria and Iran. That blunder has fed and nurtured Islamic State to become something al-Qaida could only dream about. If it weren’t for the Iran nuclear deal, we’d say it was Obama’s most catastrophic error.