What Happens When ISIS Goes Underground?

What Happens When ISIS Goes Underground?

Defeating the Islamic State could be the marquee foreign-policy accomplishment of the Trump administration. Doing so, however, will require more than just forcing the caliphate underground.


THE ISLAMIC State is on the ropes, yet the group may make a comeback. The U.S.-led coalition has driven it from much of its territory in Iraq and Syria, while most of its so-called “provinces” elsewhere in the Muslim world also have lost territory or stagnated. In July, U.S.-backed local forces took Mosul, the Islamic State’s largest stronghold in Iraq, and then in October took the Syrian city of Raqqa, the Islamic State’s capital. The caliphate may soon exist only as an idea. Once the most powerful jihadist group in modern history, the Islamic State is “now pathetic and a lost cause,” claimed Brett McGurk, the U.S. envoy for the anti–Islamic State coalition.

Despite these impressive gains, the United States is not well prepared for the group’s defeat. After losing control of key territory, the Islamic State may repeat the actions of its predecessor when the U.S.-led surge brought Al Qaeda in Iraq to the edge of defeat: go underground, disrupt politics and foster sectarianism; wage an insurgency; and then come roaring back. The United States cannot depend on its partners to counter this cycle, as local allies in Iraq and Syria are unprepared to govern and conduct effective counterinsurgency operations, while the very identity of long-term U.S. allies is unclear as Washington lacks a durable coalition in Iraq, let alone in Syria. Finally, the concepts the Islamic State promulgated are dangerous and may be exploited in the future by the Islamic State or successor organizations. As a result, the Islamic State’s campaign of regional and international terrorism, already maintained at a high level despite the group’s territorial setbacks, will likely continue and perhaps even grow in the near term.


President Donald Trump began or continued several positive counterterrorism policies—but also undertook initiatives that risk aggravating the danger the Islamic State poses. The administration improved relations with important allies like Saudi Arabia and continued the military campaign that began under former president Barack Obama to steadily drive the Islamic State from its strongholds in Iraq and Syria. However, the administration’s anti-Muslim rhetoric and policies will likely alienate some American Muslims, increasing the risk of radicalization and discouraging cooperation between these communities and police and intelligence services. In addition, the administration’s blanket embrace of the Saudi position in the Middle East will heighten sectarianism, which feeds the Islamic State and like-minded groups. Finally, a decline in foreign aid, the State Department budget and the number of national-security personnel diminishes U.S. diplomacy and the United States’ ability to resolve conflicts—all necessary for fighting jihadist groups and preventing them from spreading to new areas. Although many positive changes seem unlikely under the Trump administration, efforts to fight the Islamic State more effectively would include continuing efforts to train allied military and security services (albeit with realistic expectations). The Trump administration and U.S. leaders in general should try to bolster American resilience, which current policies are undermining.

THE ISLAMIC State has steadily suffered a series of defeats in the last two years. Most important, its base in Iraq and Syria has shrunk dramatically. By fall of 2014, the Islamic State controlled much of eastern Syria and western Iraq, including Raqqa, Mosul and Tikrit, and by spring 2015, the group captured Ramadi in Iraq and Palmyra in Syria, while its so-called province in Libya seized Sirte and nearby territory. Since then, a mix of Iraqi government forces, Kurdish militias, local tribal groups and others have pushed the group from major cities in Iraq and Syria. The Islamic State is likely to lose almost all its territory in Iraq and Syria in the coming months.

The so-called Islamic State provinces have also suffered. However, in 2016, U.S.-supported militia groups drove the Islamic State province in Libya from its base around Sirte, dispersing it to southern Libya. Elsewhere, Islamic State provinces demonstrated little dynamism in recent years—a stark contrast to 2014 and 2015 when the group seemed to expand throughout the Middle East. Some Islamic State provinces, like the one in Sinai, are succeeding with a low-level insurgency that includes bloody terrorist attacks, but these have focused on their own societies and governments, not the United States and its allies. Although analysts fret that the Islamic State might relocate—and some fighters will inevitably find a new home—there is no credible substitute for Iraq and Syria as a base, as terrorism analyst Jason Burke contends.

Funding and recruitment also dried up. The Islamic State attracted more than forty thousand foreign fighters; in some months, more than a thousand foreign fighters would join its ranks. In the last year, the number of new foreign volunteers reduced to a trickle, and the organization’s budget, which relies heavily on “taxing” local territory, also declined.

The Islamic State’s decline perpetuates itself. The group appealed to foreign fighters and funders partly by marketing itself as a winner that successfully created an Islamic state with true Islamic governance. Its biggest boasts are now its biggest failures. Fewer foreigners want to join a group incapable of defending the caliphate and clearly losing to the enemies it vowed to vanquish. Additionally, local groups in Iraq and Syria allied with the Islamic State due to its perception of constant success and feared that they would end up vulnerable when the group inevitably triumphed. As the tables turn, even groups that embrace the Islamic State’s ideology have a strong incentive to defect to its enemies.

The Islamic State recognizes its own pitiful position. As the group lost more of its strongholds, its rhetoric shifted to dismiss the importance of territorial control. Instead, the Islamic State emphasized the concept of a caliphate as the driving force behind the group’s success. Abu Muhammad al-Adnani, the Islamic State’s spokesman and senior operational figure, stated in a May 2016 recorded message,

“O America, would we be defeated and you be victorious if you were to take Mosul or Sirte or Raqqa? . . . Certainly not! We would be defeated and you victorious only if you were able to remove the Quran from Muslims’ hearts.”

Like so many other Islamic State leaders, al-Adnani is now dead.

AS THE Islamic State crumbles, its leaders will try to continue fighting rather than surrender. They plan to regroup, maintain their relevance and eventually resurge, through a mix of international and regional terrorism and local insurgency, while keeping their cause alive.

The Islamic State is not a stranger to defeat: it emerged out of Al Qaeda in Iraq, which for several years was on death’s door. In June 2010, Gen. Ray Odierno, then the commander of U.S. forces in Iraq, noted that in the last ninety days U.S. and Iraqi forces had “either picked up or killed 34 out of the top 42 Al Qaeda in Iraq leaders.” The two top Al Qaeda in Iraq leaders died in a firefight that year. By 2011, CIA director Leon Panetta declared, “we’re within reach of strategically defeating al-Qaeda.”

In response, Al Qaeda in Iraq focused on terrorism—in Iraq, not abroad—to stay relevant and to intimidate its enemies. It waged a campaign of assassination against opposing tribal leaders and other Sunnis who cooperated with the Iraqi government, killing more than 1,300 Iraqi leaders from 2009 through 2013. Due to terrorism and local killings, many Iraqis distrusted their government to secure peace and feared openly defying the jihadists. Al Qaeda in Iraq’s patience paid off: over time, the Iraqi government stepped up discrimination against Sunnis and the Syrian Civil War offered a sanctuary across the border. Taken together, these two factors allowed the group to rebuild.

The Islamic State will try to repeat this success. Al-Adnani referred to a “retreat into the desert” to rebuild forces in order to prepare for upcoming battles. This mirrors jihadis’ relocation to remote areas along Iraq’s borders after the 2007 U.S. surge.

Unfortunately, both Iraq and Syria offer promising areas for a rebirth. In Iraq, the government in Baghdad repeatedly implemented policies that discriminated against Sunnis while lacking the strength or support necessary to impose order on an unhappy population—in other words, it cannot coerce, and it seems unwilling to coopt. Shia militias are occupying many Sunni areas where the Islamic State once held sway. Already the Baghdad government is exchanging fire with Kurdish forces. Shia militias are committing abuses against local Sunnis in areas they conquered from the Islamic State. Revenge killings are common.

In Syria, the situation is even worse, with the regime of Bashar al-Assad committing unspeakable atrocities against Sunni Muslims. Tribes, Kurdish groups and other local actors that have worked with America against the Islamic State often regard each other as enemies, or at least have different interests, which will inhibit their ability to cooperate against Islamic State remnants. As their shared enemy declines and the competition for local power increases, these groups are more likely to war against each other. As such, the Islamic State will likely find many openings to exploit, allowing it to relieve pressure and ensure at least some sanctuary. In the scramble for power, many local groups may even shift from enemy to temporary ally.