In July 2017, Iraqi soldiers, backed by U.S. air strikes, liberated Mosul, the city where Abu Bakr al-Baghdadi, the leader of the Islamic State (also known as ISIS), had declared a caliphate just three years before. It was a hard-won victory. For nine grueling months, Iraq’s Counter Terrorism Service, an elite group of U.S.- trained forces, suffered heavy losses as they fought street by street to uproot ISIS fighters, who used the local population as human shields. Thousands of civilians were killed, and a million or so were displaced from their homes. Mosul’s historic monuments have been destroyed. And the city’s infrastructure lies in tatters.

But there is also much to celebrate. The liberation of Mosul ended a reign of terror that saw children brainwashed in schools, smokers publicly flogged, Yazidi women reduced to sex slaves, and gay men thrown from rooftops. The victory also struck a devastating blow to ISIS, killing thousands of its fighters, shrinking its resources, crushing its organizational capacity, and diminishing its global appeal. 

With a military victory in hand, U.S. President Donald Trump might want to declare “mission accomplished” and seek a hasty exit from Iraq. Fourteen years after the U.S. invasion, that choice is no doubt tempting. But making it would be a dangerous mistake. 

As much as Trump and other Americans may wish to end any involvement, what happens in Iraq does not stay in Iraq. ISIS has lost most of the territory it controlled in the country and is severely weakened as an organization, but the group retains the capacity to conduct attacks internationally. And U.S. support is still needed to strengthen the Iraqi state and to discourage other countries in the region from filling the power vacuum. The collapse of Iraq was instrumental in the unraveling of regional order; its stability is key to restoring a balance of power.


In March 2003, the United States invaded Iraq on the assumption (which later proved incorrect) that Iraqi President Saddam Hussein was developing weapons of mass destruction. Military success was quick—the U.S.-led coalition toppled Saddam’s government within a few weeks—but political success proved more elusive. In 2003, the Coalition Provisional Authority dismissed Iraqi civil servants and dissolved the security forces. These decisions led to the collapse of the state and civil war, which allowed al Qaeda in Iraq to gain a foothold and Iran to expand its influence. During U.S. President George W. Bush’s second term, however, the United States managed to reverse a seemingly bleak prognosis. The surge of additional U.S. troops into the country in 2007, combined with the cooperation of Sunni tribes (the so-called Sunni Awakening), dramatically reduced sectarian violence and brought about the defeat of al Qaeda in Iraq.

A statue of Saddam Hussein falls in Baghdad, April 2003.
A statue of Saddam Hussein falls in Baghdad, April 2003
Goran Tomasevic / Reuters

When U.S. President Barack Obama took office, in 2009, both the Americans and the Iraqis believed that the sectarian civil war was over and that the country was finally on the right track. But rather than capitalizing on these successes to cajole Iraqi politicians toward compromise, the Obama administration disengaged. The 2010 Iraqi election marked an inflection point. When Iraqiya, the nationalist, nonsectarian political party led by Ayad Allawi, narrowly defeated the Dawa Party, led by Nouri al-Maliki, the incumbent prime minister, the Obama administration failed to uphold the right of the winning bloc to have the first go at forming a government. Instead, it signaled its desire to keep Maliki in power, despite the stipulations of the Iraqi constitution and the objections of Iraqi politicians. 

The Obama administration insisted that Maliki was an Iraqi nationalist and a friend of the United States. But in reality, the decision to keep him in place played into the hands of Iran. Tehran pressured the anti-American Shiite cleric Muqtada al-Sadr, one of Maliki’s most outspoken foes, to align his powerful political bloc with Maliki’s coalition, a move that was instrumental in securing another term for the prime minister. In exchange for Iran’s help in forging the alliance with Sadr, Maliki agreed to ensure the complete withdrawal of U.S. forces from Iraq by 2011, when the status-of-forces agreement between the two countries was set to expire. 

Instead of marking the peaceful transition of power in a new democratic system, the 2010 election undermined confidence that change could come about through politics. Secure in his seat for a second term, Maliki reneged on his promises to the Sunni Awakening. He labeled Sunni politicians as “terrorists,” driving them out of the political process, and he ordered the security forces to violently crush Sunni dissent. In so doing, Maliki created conditions that allowed a new group to rise up out of the ashes of al Qaeda in Iraq. ISIS, as it came to be known, proclaimed itself the defender of Sunnis against Maliki’s regime. Feeling betrayed and discriminated against by the government, many Sunnis determined that ISIS was the lesser of two evils. 

Maliki further undermined Iraq’s fledgling democratic institutions by politicizing them. These moves were particularly damaging to the military, where Maliki replaced many effective Iraqi security forces commanders—whom he regarded as too close to the Americans—with loyalists.

The Obama administration’s decision to disengage from Iraq ultimately brought about conditions that required it to reengage.

The Obama administration’s decision to disengage from Iraq ultimately brought about conditions that required it to reengage. By 2014, ISIS had taken control of a third of the country, and the Iraqi army—trained and equipped by the United States at a cost of billions of dollars—had disintegrated, leaving behind its U.S.-supplied equipment for ISIS to capture. Confronted with a well-armed terrorist group and a weak state whose army had collapsed, the Obama administration withdrew its support from Maliki and demanded that he be replaced before once again dispatching U.S. forces to Iraq. 


Now, with ISIS unseated from Mosul and the 2018 elections on the horizon, Iraq has reached another inflection point. The current fragmentation of Iraq’s political landscape provides a chance for meaningful cross-sectarian coalition building. But there is also a risk that other countries in the region might seize the opportunity to increase their influence as Iraqi politicians compete with one another for power.

Maliki’s replacement as prime minister, Haider al-Abadi has sought to balance American and Iranian support and has tried to remain neutral in regional power struggles. He has also adopted a much more inclusive approach to domestic politics. To stay in power, he might form political alliances with a range of factions. One potential ally is Sadr, who has already announced his intention to form a political alliance with Allawi, the politician whose coalition defeated Maliki in 2010. Abadi may also find allies among Shiite Islamist political parties, such as the newly formed al-Hikma group, led by Ammar al-Hakim. The recent victory against ISIS has strengthened Abadi’s position, but he still needs to build up his own power base. 

Abadi also faces strong competition. Still smarting from being deposed, Maliki is constantly working to undermine Abadi and advance his anti-American and pro-Iranian agenda. Another key player is Hadi al-Ameri, the leader of the Badr Organization, a Shiite militia–cum–political party intent on deepening Iraq’s ties to Iran and attacking secular activists. 

Sunni leaders, meanwhile, remain divided and disgraced, and the old guard has been unwilling to step aside to allow a younger generation of politicians to emerge. Shiite leaders accuse the Sunnis of being beholden to neighboring countries such as Saudi Arabia and Turkey—a fear stoked by the Sunnis’ habit of holding political conferences abroad. Further complicating reconciliation is the desire for revenge against those who collaborated with ISIS and a widespread suspicion that many Sunnis initially welcomed ISIS into their cities. 


The Kurds, in contrast, find themselves in a stronger position, which they hope to leverage in their bid for independence. Kurdish ambitions for statehood date back to the collapse of the Ottoman Empire, when the imperial powers drew new borders in the Middle East. Despite promises to the contrary, the Kurds did not receive a country; instead, their lands were incorporated into Iran, Iraq, Syria, and Turkey.

But over the last few years, their situation has changed. During the campaign against ISIS, the Iraqi Kurds received weapons directly from the international community (rather than through Baghdad), and they were able to extend the territory under their control to include the multiethnic and oil-rich city of Kirkuk. These developments generated momentum, which led Masoud Barzani, the president of the Kurdistan Regional Government, to schedule a referendum on independence for September 25, 2017.

To achieve independence, however, the Kurds must surmount numerous obstacles, both internal and external. Iran and Turkey both strongly objected to the referendum out of the fear that it might strengthen the Kurdish secessionist movements in their respective countries. The United States also continues to support a unified Iraq, and U.S. Secretary of State Rex Tillerson pushed the Kurds to postpone their referendum. Meanwhile, Barzani faces challenges at home, as well. He has overstayed his legally mandated term as president, and young Kurds in particular have grown increasingly critical of his government’s corruption and mismanagement. To make matters worse, low oil prices and ongoing disputes with Baghdad have left the salaries of many Iraqi Kurds unpaid and lowered the standard of living.


In Iraq, domestic political dynamics are inextricably linked to circumstances beyond the country’s borders. Concern about the level of Iranian influence is particularly widespread. During the campaign to defeat ISIS, Iran not only provided military advisers; it also supported certain Shiite militias, which it wants to maintain in order to extend its political influence in Baghdad and secure the land route from Iran to Lebanon.

In Iraq, domestic political dynamics are inextricably linked to circumstances beyond the country’s borders.

These Iranian-backed militias are part of the so-called Popular Mobilization Units, which were formed in response to the 2014 fatwa of Ayatollah Ali al-Sistani that called on Iraqis to rise up to defend their country against ISIS. Because of their role in preventing ISIS from marching on Baghdad, the Popular Mobilization Units enjoy wide support on the Shiite street, and some of their leaders are now looking to convert their military successes into political power. But these militias undermine the legitimacy of the state; their continued presence keeps Iraq from becoming strong enough to push back against Iranian influence. And widely disseminated reports of the torture and murder of ISIS suspects at their hands have instilled fear among the Sunni population.

Despite having welcomed Tehran’s support in the past, the Iraqi leadership is now taking steps to balance Iranian influence by making significant overtures to Saudi Arabia. In February 2017, Adel al-Jubeir became the first Saudi foreign minister to visit Baghdad since Iraq and Saudi Arabia cut ties in 1990, when Saddam invaded Kuwait. Later in 2017, Abadi and Qassim al-Araji, Iraq’s interior minister, each paid separate visits to Riyadh. Even Sadr, a Shiite cleric, visited Saudi Arabia and the United Arab Emirates in August 2017, where he presented himself as an Arab and Iraqi nationalist, thus poking Iran in the eye. 

For now, however, Tehran still has the upper hand. Iran has taken advantage of Iraq’s volatility to cultivate clients in Baghdad and establish land corridors to the Mediterranean Sea. These moves are not simply about resupplying Shiite militias such as Hezbollah or evading sanctions by establishing a presence beyond Iran’s official borders. They are also a reflection of Tehran’s ambition to extend its sphere of influence and create strategic depth. Iran is now the external power with the most influence in both Iraq and Syria. Left unchecked, this could lead not just to an Iranian-Saudi confrontation but to an Iranian-Israeli one as well. Increased Iranian power in the region exacerbates Israel’s fear that destructive weapons in Syria might fall into the hands of its enemies, many of whom are supported by Tehran. Already, Israel has launched strikes against several Syrian military bases that are known to produce chemical weapons and other sophisticated tools of war.

The Iraqi army after liberating a village from ISIS militants south of Mosul, October 2016
Thaier Al-Sudani / Reuters


So what should Washington do? Both Bush and Obama made disastrous decisions on Iraq during their first terms. It was only in their second terms that they came up with sensible policies to address their mistakes. These initial missteps cost the United States influence and credibility. But given the importance of U.S. military support in the fight against ISIS, Washington has new leverage, and it should take care not to squander it. The defeat of ISIS in Mosul should not lull the Trump administration into a false sense of security. As the past decade and a half have made clear, nothing in Iraq is irreversible.

That includes Iranian gains. To reverse those, Iraqi politicians will have to reach an agreement on politically sensitive questions such as the nature of governance and resource distribution in order make the central government less vulnerable to external meddling. This, in turn, will require a commitment to strengthening institutions, imposing the rule of law, and cracking down on corruption. (Iraq ranks 166th out of 176 countries on Transparency International’s Corruption Perceptions Index.) 

The United States can help. But doing so would require it to view its national interests in Iraq through a wider lens than simply counterterrorism. This would entail sustained support for Iraqi institutions and a greater commitment to pushing back against Iranian expansionism, which is in itself one of the factors that rallies Sunni extremists.

In terms of Iraqi institutions, the United States should prioritize providing security assistance to the security forces and intelligence services that have proved themselves in the rollback of ISIS. Support for the Counter Terrorism Service has arguably been the most successful U.S. initiative in Iraq since 2003. Composed of Iraqis of all different backgrounds, the Counter Terrorism Service maintained morale and cohesion despite enduring heavy losses in the brutal battle to liberate Mosul. U.S. support for these forces should be continued and reinforced.

To secure the recent military gains, the United States should also help build the capacity of Iraqi battalions to control the western desert between Iraq and Syria and help bolster Iraq’s intelligence, surveillance, and reconnaissance capabilities. To increase the legitimacy of the state, Washington should advise security-sector reform, including bringing militias supportive of the state into the fold of the Iraqi security forces—while disarming, demobilizing, and reintegrating into Iraqi society those loyal to Iran.

All this assistance need not entail thorny negotiations; nor would such support require U.S. bases or combat forces. The United States can work toward these goals with advisers and trainers under the terms of the existing Strategic Framework Agreement with Iraq. 

The United States must also develop a clear Kurdish policy. If separation is to occur—whether in the form of confederation or independence—the process should be negotiated between Baghdad and Erbil, endorsed by neighboring countries, and recognized by the international community. Either way, the United States should support the revitalization of the UN’s efforts to determine, district by district, the border between Kurdistan and the rest of Iraq. This process should also consider granting Kirkuk special status in recognition of its diverse population, contested history, and oil wealth. No Iraqi prime minister can afford to lose Kirkuk. International mediation could help broker a compromise.

While the negotiations are ongoing, Washington should help reduce the risk of conflict between Arabs and Kurds. In 2009, during another period of heightened tensions, the U.S. military facilitated cooperation between the Iraqi security forces and the Kurdish peshmerga in the disputed territories. Going forward, the United States should again help the Iraqis coordinate among the different security forces active in the area, which now also include the Kurdistan Workers’ Party, or PKK (the Turkish Kurdish guerrilla group), and the Popular Mobilization Units. And when approaching the Kurdish question, Washington must remain mindful of Turkey’s concerns in order to alleviate the risk that Turkish forces will intervene in northeastern Syria or that Turkey will gravitate toward Iran and Russia. 

No plan for Iraq is complete without taking into account the regional context. Building on Iraq’s improving relations with Sunni countries, the United States needs to encourage Saudi Arabia and other Gulf states to support Abadi’s government by investing in the reconstruction of Mosul and other areas devastated by ISIS. Mosul was once renowned across the region as a cosmopolitan city, with an excellent university, a successful merchant class, and a diverse population of Arabs, Christians, Kurds, Shabaks, Turkmen, and Yazidis. Its reconstruction would restore pride and provide young Iraqis with opportunities to live for rather than dystopian causes to die for. Such assistance, provided through the Iraqi government, would help balance Iranian influence and give Iraqi Sunnis hope for a better future.

Many of Trump’s aides have considerable experience with Iraq, including James Mattis, his secretary of defense; H. R. McMaster, his national security adviser; and John Kelly, his chief of staff. One can hope that Trump’s advisers might push him to select the least bad options from the choices available. But implementing the resulting policies would require a skillful secretary of state supported by a strong State Department. And at the moment, the State Department lacks the resources to play that crucial role.

The Trump administration should learn from the mistakes of the past. At the end of the day, ISIS is not the cause of Iraq’s problems but a symptom of failed governance. And if the United States disengages now, Trump’s successor may have to put American boots on the ground yet again, to fight the son of ISIS.

You are reading a free article.

Subscribe to Foreign Affairs to get unlimited access.

  • Paywall-free reading of new articles and a century of archives
  • Unlock access to iOS/Android apps to save editions for offline reading
  • Six issues a year in print, online, and audio editions
Subscribe Now