Mosul, Iraq’s second-largest city, has long been hard for the central government to control because of its combustible mix of Arabs and Kurds. The first time I visited Mosul was in August 2003 when a tenuous calm was maintained by the 101st Airborne Division. Its commander, a then-obscure two-star general named David Petraeus, had on his own initiative opened the Syrian border to trade, struck deals with Syria and Turkey to provide badly needed electricity, restored telephone service, and held elections to elect local leaders. Along the way he also managed to kill Saddam Hussein’s poisonous offspring Uday and Qusay.
This kept militants at bay, but they returned with a vengeance after the 101st pulled out in 2004, to be replaced by a smaller American unit whose officers were less attuned to the demands of civic action. Mosul became a hotbed of Saddamist and Islamist militants, as I saw for myself in February 2008 when, during another visit, the U.S. Army convoy in which I was riding was hit by a “complex ambush”: The Humvee in front of mine hit a bomb concealed in a big puddle, and insurgents opened machine gun fire from the left. Luckily no one in our unit was hurt, but a bystander had his arm sliced off by a flying piece of the Humvee’s engine.
Mosul was the last major city to be pacified by the successful “surge.” It took until at least 2010 before it was secure. But now that achievement has been undone. Black-clad fighters from the Islamic State of Iraq and Syria (ISIS), as Al Qaeda in Iraq has rebranded itself, stormed into Mosul last week and seized control. Dispirited Iraqi soldiers ran away rather than fight. Many were so eager to escape that their discarded uniforms littered the streets. ISIS freed more than 2,000 of its fighters from prisons and seized copious stocks of money, ammunition, and weapons—many of the latter provided by the United States to Iraqi forces.
This was only the latest and most alarming advance for this extremist group, which has risen out of its grave to display dismaying strength in recent years. In January, ISIS seized Fallujah and holds it still—a loss that, like Mosul, is particularly painful to American veterans who sacrificed so much to wrest control of those cities from militants. Following up on their success in Mosul, ISIS fighters advanced south to seize, at least temporarily, Tikrit, Saddam -Hussein’s hometown, and Baiji, home to Iraq’s largest oil refinery, which supplies Baghdad with much of its electricity. Their next targets are certain to be Baqubah and Baghdad. In the capital, ISIS has already inflicted devastating casualties with a series of car bombings. Iraq Body Count calculates that some 9,500 people were killed in Iraq last year, the highest total since 2008. Worse is surely yet to come as Shiite militant organizations such as Asaib Ahl al-Haq and Kataib Hezbollah respond to Sunni atrocities with atrocities of their own.
This is not just a problem for Iraq. ISIS, as the name implies, has spread across the border into Syria, where it has been showing increasing strength amid the chaos of the Syrian civil war, in no small part because the United States has done so little to aid the non-jihadist opposition to Bashar al-Assad. ISIS is well on its way to carving out a fundamentalist caliphate that stretches from Aleppo in northern Syria to Mosul in northern Iraq. The post-World War I borders of the Middle East seem to be unraveling. Syria is being split into two entities, one controlled by Sunni Islamists, the other by Hezbollah and the Iranian Quds Force and their Alawite proxies. Iraq is being split into three, with a prosperous and stable Kurdish state, a fundamentalist Sunni Triangle state controlled by ISIS, and the Shiite portions of the country under the sway of militants backed by Iran. Iran is directly involved in the fighting in both countries: It has already sent Quds Force troops to Syria and now reportedly to Iraq as well. The only thing that remains to be determined is whether Shiite or Sunni extremists will control the capital—the new battle for Baghdad, which has already begun, is likely to be even bloodier than the previous installment from 2003 to 2008.
It is hard to exaggerate how much of a disaster this is, not only for Syria and Iraq and their neighbors, but for the United States. Rising oil prices (crude oil rose to over $112 a barrel last week), which could torpedo a weak economic recovery, are just the start of it. Senior intelligence officials have testified recently that they fear Syria could become a launching ground for attacks against the United States. Similar concerns now must extend to Iraq. Certainly, the track record of Islamist militants suggests that whenever they control a piece of terrain—whether Afghanistan before 2001 or Mali in 2013—they immediately set up training camps for foreign jihadists, some of whom then filter back to their home countries to commit atrocities. At the least, neighboring states such as Jordan and Saudi Arabia will be destabilized by the growing strength of ISIS; at the worst, the American homeland and Americans overseas will be threatened.
How did this disaster come about and what can be done about it? Critics of the Iraq war affix blame to President George W. Bush’s decision to invade in 2003. But there is no guarantee that, even absent American intervention, Saddam Hussein would have had any more luck staying in power than other Arab despots. A civil war might well have broken out in Iraq anyway, as has been the case in Syria and Libya. It is true that Bush’s mismanagement from 2003 to 2007 aggravated the situation, especially his foolish decisions to disband the Iraqi Army without sending enough U.S. troops to fill the vacuum and to purge Baathists from the government in a process that was hijacked by Shiite militants such as Ahmad Chalabi. This created the lawless conditions out of which both Sunni and Shiite extremists arose...