“What I would not have had done was left 10,000 troops in Iraq that would tie us down.” So said President Obama in Tuesday night’s debate. And he was speaking the truth, as readers of Michael Gordon and Bernard Trainor’s fine new book The Endgame can attest, even though Obama was ostensibly committed in 2011 to maintaining a continuing U.S. troop presence in Iraq.

Gordon and Trainor note that Obama steadily whittled down the number of troops he was willing to keep in Iraq. Commanders wanted more than 20,000 initially, but the president eventually was willing to provide fewer than 5,000. And he insisted on such strict conditions in Status of Forces negotiations—the Obama administration demanded that the Iraqi parliament ratify any grant of immunity to U.S. troops even though there was no legal or political requirement to do so—that Iraqi leaders got a clear signal that the U.S. wasn’t committed to their country. That made them less willing to compromise in negotiations. And Obama did not give enough time to those negotiations in any case—they only began in the middle of 2011 even though the last such negotiations, in 2008, had taken nearly a year. Then, when the negotiations ran into obstacles, Obama pulled the plug and trumpeted the return of the troops.

Obama got what he wanted—at least for the short term. He can brag to voters that he got out of Iraq. But the long-term consequences may not be to his liking—at least if he is concerned about his legacy. As retired Gen. Jack Keane, a key architect of the surge, notes in this Wall Street Journal op-ed, “Al Qaeda in Iraq has doubled in size in the year since U.S. troops left the country.” That’s not only a grave danger for the U.S. and our allies in the region—it’s also a grave danger to the long-term reputation of a president whose signature foreign policy achievement has been the killing of al-Qaeda’s leader. Osama bin Laden may be dead but, as Keane notes, al-Qaeda affiliates in Iraq, Libya, Yemen, Somalia, Syria, and Sinai are very much alive. Obama can’t be blamed for all of these developments—al-Qaeda affiliates were well entrenched in Somalia and Yemen before he came into office. But their growth in Libya, Syria, Sinai, and Iraq have occurred on his watch and have been spurred to some extent by his misguided policies—especially true in the case of Iraq.

Iraq may now look to Obama as a shining exemplar of his foreign policy vision. But I predict that in a few years it will be widely recognized as one of his biggest failures.