The fall of Mosul and the likely fall of Raqqa won’t be the end of the Islamic State. The group has already reverted to its insurgent roots in some of the areas that have been lost. It also still controls some territory. The Islamic State will continue to function as a guerrilla army, despite suffering significant losses. In May, the Office of the Director of National Intelligence (ODNI) assessed that even though it was losing significant ground, the Islamic State “will likely have enough resources and fighters to sustain insurgency operations and plan terrorists [sic] attacks in the region and internationally” going forward. Unfortunately, I think ODNI’s assessment is accurate for a number of reasons, some of which I outline below. I also discuss some hypothetical scenarios, especially with respect to returning foreign fighters or other supporters already living in Europe or the U.S.
Recent history. The Islamic State’s predecessor quickly recovered from its losses during the American-led “surge,” capitalizing on the war in Syria and a politically poisonous environment in Iraq to rebound. Indeed, Abu Bakr al Baghdadi’s organization grew into an international phenomenon by the end of 2014, just three years after the U.S. withdrawal from Iraq was completed. Baghdadi’s men did this while defying al Qaeda’s leaders and competing with rival jihadist groups. This recent history should give us pause any time we hear rhetoric that sounds too optimistic about the end of the Islamic State’s caliphate. The enterprise has had enough resources at its disposal to challenge multiple actors for more than three years. There is no question that the Islamic State’s finances, senior personnel, and other assets have been hit hard. But it is premature to say its losses amount to a deathblow.
Uncertainty regarding size of total membership. While it is no longer at the peak of its power, the Islamic State likely still has thousands of dedicated members. We don’t even really know how many members it has Iraq and Syria, let alone around the globe. Previous U.S. estimates almost certainly undercounted the group’s ranks. In September 2014, at the beginning of the US-led air campaign, the CIA reportedly estimated that the Islamic State could “muster” between 20,000 and 31,500 fighters. This figure was “more than three times the previous estimates,” CNN noted. By December 2016, the U.S. military was estimating that 50,000 Islamic State fighters had been killed. By February 2017, U.S. Special Operations command concluded that more than 60,000 jihadists had perished. Two months later, in April 2017, the Pentagon reportedly estimated that 70,000 Islamic State fighters had been killed.
Taken at face value, these figures (beginning with the September 2014 approximation) would suggest that Abu Bakr al Baghdadi’s enterprise was able to replace its entire force structure more than two times over, while fighting multiple enemies on numerous fronts. This is, of course, highly unlikely. Even with its prolific recruiting campaign, it would be impossible for any cohesive fighting organization, let alone one under the sustained pressure faced by the Islamic State, to train, equip and deploy fighters this quickly. It is far more likely that the U.S. never had a good handle on how many jihadists are in its ranks and the casualty figures are guesstimates. The purpose of citing these figures is not to re-litigate the past, but instead to sound a cautionary alarm regarding the near-future: We likely do not even know how many members the Islamic State has in Iraq and Syria today.
The Islamic State is an international organization. Since November 2014, when Abu Bakr al Baghdadi first announced the establishment of “provinces” around the globe, the Islamic State’s membership grew outside of Iraq and Syria. This further complicates any effort to estimate its overall size. Some of these “provinces” were nothing more than small terror networks, while others evolved into capable insurgency organizations in their own right. The Libyan branch of the caliphate temporarily controlled the city of Sirte. Although the jihadists were ejected from their Mediterranean abode by the end of 2016, they still have some forces inside the country. Similarly, Wilayah Khorasan (or Khorasan province), which represents the “caliphate” in Afghanistan and Pakistan, seized upwards of ten districts in Afghanistan as of early 2016, but has since lost ground. More recently, jihadists in the Philippines seized much of Marawi, hoisting the Islamic State’s black banner over the city. Wilayah Sinai controls at least some turf, and is able launch spectacular attacks on security forces. It was responsible for downing a Russian airliner in October 2015. Other “provinces” exist in East Africa, West Africa, Yemen and elsewhere.
In May, the Office of the Director of National Intelligence (ODNI) reported that the so-called caliphate “is seeking to foster interconnectedness among its global branches and networks, align their efforts to ISIS’s strategy, and withstand counter-ISIS efforts.” Gen. John Nicholson, the commander of U.S. Forces-Afghanistan, has said that Wilayah Khorasan went through an “application process” and the Islamic State mothership provided it with “advice,” “publicity,” and “some financial support.” Although it is impossible to judge the extent of the Islamic State’s cohesion, as much of the data is not available, there is at least some connectivity between the group’s leadership and its “provinces” elsewhere. This is best seen on the media side, as the organization is particularly adept at disseminating messages from around the globe in multiple languages, despite some recent hiccups in this regard.
While their fortunes may rise or fall at any given time, this global network of Islamic State “provinces” will remain a formidable problem for the foreseeable future. Not only are they capable of killing large numbers of people in the countries they operate in, this structure also makes tracking international terrorist travel more difficult. For instance, counterterrorism officials have tied plots in Europe to operatives in Libya. This indicates that some of the Islamic State’s “external plotters,” who are responsible for targeting the West, are not stationed in Iraq and Syria. The U.S.-led air campaign has disrupted the Islamic State’s “external operations” capacity by killing a number of jihadists in this wing of the organization. But others live.
The cult of martyrdom has grown. A disturbingly large number of people are willing to kill themselves for the Islamic State’s cause. The number of suicide bombings claimed by the so-called caliphate dwarfs all other jihadist groups, including al Qaeda. In 2016, for instance, the Islamic State claimed 1,112 “martyrdom operations” in Iraq and Syria alone. Through the first six months of 2017, the organization claimed another 527 such bombings (nearly three-fourths of them using vehicle-borne improvised explosive devices, or VBIEDs) in those two countries. These figures do not include suicide attacks in other nations where Abu Bakr al Baghdadi’s loyalists are known to operate.
To put the Islamic State’s current “martyrdom operations” in perspective, consider data published by the Washington Post in 2008. According to the Post, there were just 54 suicide attacks in all of 2001, when al Qaeda’s “martyrs” launched the most devastating terrorist airline hijackings in history. The Islamic State currently eclipses that figure every month in Iraq and Syria, averaging 93 suicide bombings per month in 2016 and 88 per month so far in 2017. Many of these operations are carried out by foreign fighters.