What is the Threat to Europe?

While the threat in the United States consists of attacks inspired — or in one case enabled — by ISIS, the threat in Europe is more severe, consisting of a mixture of attacks directed by ISIS and its affiliates as well as homegrown ISIS-enabled and ISIS-inspired attacks.

While the United States has experienced no attacks directed by foreign terrorist organizations since 9/11, there have been five ISIS-directed attacks in Europe since 2014:

• A May 2014 attack in which Mehdi Nemmouche killed four people in a shooting at the Jewish Museum of Belgium in Brussels. Nemmouche had been in contact with Abdelhamid Abaaoud, the mastermind of the November 2015 Paris attacks, and had guarded Western hostages held by ISIS core in Syria.¹
• An August 2015 foiled attack on a train in Oignies, France, whose perpetrator, Ayoub El-Khazzani, traveled to Europe with Abaaoud.²
• The November 2015 attacks in Paris, which killed 130 people, by terrorists trained in Syria and sent back to Europe by ISIS. The Paris attacks showed how a group of terrorists trained by a terrorist organization can mount operations more lethal than those carried out by homegrown terrorists without such training.
• The March 2016 bombing of the Brussels airport and metro, killing 32 people, by members of the same cell that conducted the attack in Paris.
• The May 2017 bombing of an Ariana Grande concert in Manchester, England, which killed 22 people, by Salman Abedi. Abedi had trained and been in close contact with ISIS operations planners in Libya.

The five ISIS-directed attacks in Europe since 2014 killed 188 people, almost two times the death toll of all deadly jihadist attacks in the United States since 9/11.³

Europe may have turned the corner regarding the immediate threat of ISIS-directed attacks. It has not seen an ISIS-directed attack since May 2017, and it has not seen an attack directed by ISIS core rather than an affiliate since March 2016. With the demise of ISIS’ territorial state in Syria and Iraq, attacks in Europe are increasingly likely to be ISIS-enabled or ISIS-inspired but not ISIS-directed. Where they are ISIS-directed, they are likely to be directed by ISIS’ affiliates rather than its core in Iraq and Syria.

In its 2018 report, Europol cited a “decrease in sophistication” in attack plots in the European Union in 2017.⁴ In addition, according to Europol, the number of arrests for jihadist terrorism in Europe stabilized and declined slightly to 705 in 2017 from 718 the previous year, after increasing every year from 2013 through 2016.⁵ However, this decline is far less clear than that in the United States.

With the demise of ISIS’ territorial state in Syria and Iraq, attacks in Europe are increasingly likely to be ISIS-enabled or ISIS-inspired but not ISIS-directed.

Despite these promising signs, Europe faces a continued and substantial threat. While Europe may be turning the corner with regard to directed, sophisticated plots, Europol reported that the number of foiled, failed or successful jihadist attacks more than doubled from 13 in 2016 to 33 in 2017.⁶

New America’s research, which tracks failed and successful attacks, suggests a similar trend. The number of attacks per year grew through 2017. This growth was driven by a steady increase in the number of attacks inspired by jihadist ideology in Europe but not known to have been directed or enabled by ISIS, even as attacks known to have closer ties to ISIS tapered off. As of the end of August, 2018 is not on pace to match the number of attacks in 2017. This may change, however, as the year ends.

Europe has experienced seven ISIS-enabled attacks since 2014,⁷ compared to one in the United States. Twenty people have died in ISIS-enabled attacks in Europe, while no one other than the perpetrators has died in an ISIS-enabled attack in the United States. The last⁸ ISIS-enabled attack in Europe occured in April 2017, when Rakhmat Akilov drove a truck into a crowd in Stockholm, Sweden, killing five people. Before the attack, Akilov shared images of his target and received a green light for the attack from his contacts via encrypted message.⁹

Finally, there have been 46 attacks inspired by jihadist ideology in Europe that have not been directed or enabled by ISIS or other foreign terrorist organizations since 2014. These inspired attacks have killed 141 people in Europe since 2014, more than jihadist terrorists have killed in the United States during the 17 years since the 9/11 attacks.

Europe faces a more severe threat than the United States in large part due to four major factors: the large number of European foreign fighters, the larger and more developed nature of European jihadist networks, the marginalization of Muslims within Europe, and Europe’s geographic proximity to conflict zones.

Foreign Fighters

The first factor is the far larger number of foreign fighters who left for Syria and Iraq from Europe and the correspondingly large number of returnees. In its 2018 report, Europol estimated that about 5,000 Europeans had traveled to conflict areas in Syria and Iraq. By late 2017, Europol estimated, those in Syria numbered 2,500, with 1,500 having returned home and 1,000 having died.¹⁰

These numbers are far greater than the number of Americans who have traveled to fight in Syria and Iraq. According to the FBI, 300 Americans have “traveled or attempted to travel to Syria and Iraq to participate in the conflict,” a number that appears to include those who fought with any group.¹¹ In addition, many of these Americans were arrested before setting foot in the conflict zone. Even with such caveats, the number of American “fighters” is more than 16 times smaller than the number of European fighters who actually traveled to Syria or Iraq.

The far larger number of European fighters is confirmed by ISIS’ own records. A set of 3,577 ISIS personnel records examined by New America contained 34 times as many fighters reporting residence in Western Europe than fighters reporting residence in the United States.

Correspondingly, the number of American returnees — likely in the tens — is also far lower than the 1,500 European returnees. In March 2015, then-Director of National Intelligence James Clapper stated that about 40 Americans had returned from Syria, though he suggested that some had gone for “humanitarian purposes.”¹² Research by New America as well as the George Washington University Program on Extremism has identified fewer than 15 American returnees from Syria.¹³

3,577 ISIS personnel records examined by New America contained 34 times as many fighters reporting residence in Western Europe than fighters reporting residence in the United States.

The large number of European foreign fighters increases the threat to Europe in several ways. First, such fighters were behind the far deadlier and more sophisticated set of directed attacks that hit Europe. However, the impact of returned European fighters is not limited to such directed attacks. Returnees can also act as organizers and facilitators, using their experience and knowledge to help build jihadist networks — whether to enable attacks by others or to enable terrorist travel, propaganda and fundraising activity.¹⁴

Beyond the threat of returnees from Syria conducting directed attacks or coordinating homegrown attacks by building networks, many of the returnees remain potential sources of inspired violence without direction from ISIS itself. The large radicalized population will remain a concern regardless of the state of ISIS control over operations.

The contours of the foreign fighter and returnee problem in Europe have shifted over time. For the time being, the flow of fighters to ISIS has been cut to at most a trickle. According to Europol’s 2018 report, “In 2017 there were considerably fewer EU-based FTFs [foreign terrorist fighters] travelling to conflict zones.”¹⁵ This continues a longer trend. Europol’s 2017 report assessed, “There is a decrease in the numbers of individuals travelling to the conflict zones in Syria/ Iraq to join the jihadist terrorist groups as foreign terrorist fighters.”¹⁶

In May 2017, then-National Counterterrorism Center Director Nicholas Rasmussen commented, “The good news is that we know that the rate of foreign fighters traveling has steadily declined since its peak in 2014.”¹⁷ Today, the flow to Syria and Iraq is essentially nonexistent.

That said, there are signs that there is still interest on the part of some militants and some level of sustained facilitation network activity for travel to conflict zones. For example, Europol notes that in June 2017, a Dutch man successfully reached ISIS in Syria (the first known case since November 2016).¹⁸ A search warrant in Minnesota alleges that an American attempted, but failed, to reach Syria via Europe in 2017 as well.¹⁹ Such cases do not provide reason to contest the finding that the number of travelers has declined precipitously. They do, however, warrant continued attention, particularly as the flow of fighters may increase again if another conflict becomes a popular field of jihad.

The flow of foreign fighter returnees back to Europe has also declined substantially. According to Europol’s 2018 report, in 2017 there was a “diminishing number of returnees” in part due to the difficulty of leaving ISIS territory as a result of military actions against ISIS.²⁰ In July 2017 Rasmussen noted, “I look at the problem now as not so much as one of quantity but as one of quality,” emphasizing not the number of returnees but the skills that the small number of those who might return have obtained and how they might use them.²¹

There is a wild card with regard to European foreign fighter returnees, which is the unclear fate of the reportedly large number of Europeans currently imprisoned or detained in Syria and Iraq or otherwise remaining in the conflict zone. European countries have so far refused to take back hundreds of detained European fighters.²² This has resulted in some detained European fighters reportedly being released.²³ This produces the possibility that such fighters may return without being arrested at a later date, increasing the threat in Europe.

Jihadist Networks

The second factor compounding the threat in Europe is the existence there of stronger, more developed jihadist networks than exist in the United States. One reason ISIS was able to successfully conduct the November 2015 Paris attacks was that the attackers relied on a support network of at least 20 other people.²⁴ Similarly, Belgium tried 46 members of the radical group Sharia4Belgium who traveled to fight in Syria or helped others to do so.²⁵ Those 46 are only a small portion of the larger Sharia4Belgium network.

As noted above, according to Europol, European states arrested 705 people in 2017 for jihadist terrorism, 718 people in 2016, and 687 in 2015.²⁶ That is more jihadist terrorism-related arrests each year than have been made in the United States since 9/11.²⁷ Over the three-year period from 2015 through 2017, European states arrested more people for jihadist terrorism-related crimes than the FBI reports having open investigations of ISIS-related crimes.²⁸

Marginalization and Anti-Muslim Feeling

The third factor is that Europe faces more substantial challenges in successfully integrating its Muslim population than does the United States, and is thus likely to continue to struggle with a significant homegrown threat rooted in these challenges. In particular, the lack of opportunities and the identity challenges facing second-generation Muslim immigrants in Europe will likely continue to radicalize some for the foreseeable future.²⁹

As a result of war, revolution, and poor economic and social conditions in the Middle East and North Africa, there has been an unprecedented wave of immigration from Muslim-majority countries into Europe in the past three years. Germany alone has taken in more than 1 million refugees and asylum seekers.³⁰ European countries lack the ideological framework the United States has in the shape of the “American Dream,” which has helped to successfully absorb wave after wave of immigration, including Muslim Americans who are generally well integrated into American society.

The lack of opportunities and the identity challenges facing second-generation Muslim immigrants in Europe will likely continue to radicalize some for the foreseeable future.

There is no analogous French Dream or German Dream. The proportion of the French prison population that is Muslim is estimated to be around 60 percent, yet Muslims account for only about 8 percent of France’s total population.³¹ Muslim citizens in France are 2½ times less likely to be called for a job interview than similar Christian candidates, according to researchers at Stanford University.³² Many French Muslims live in grim banlieues, the suburbs of large French cities (similar to housing projects in the United States), where they find themselves largely divorced from mainstream French society. According to the Renseignements Généraux, a police agency that monitors militants in France, half the neighborhoods with a high Muslim population are isolated from French social and political life. The French term for these neighborhoods is equivalent to “sensitive urban zones,” where youth unemployment can be as high as 45 percent.³³ In Belgium there is a similar story: Twenty to 30 percent of the prison population is Muslim, yet Muslims make up only 6 percent of the overall population.³⁴

It is not surprising that many of the perpetrators of attacks in Europe come from these economically marginalized communities or have spent time in French and Belgian prisons, which can function as universities of jihad. The members of the ISIS cell responsible for the November 2015 attacks in Paris that killed 130 and the March 2016 attacks in Brussels that killed 32 had bonded through criminal activities or in prison.³⁵ Abdelhamid Abaaoud and Salah Abdeslam, the cell’s masterminds, were childhood friends who grew up in the impoverished Brussels neighborhood of Molenbeek. In 2010, the men were arrested and spent time in the same prison. Ibrahim Abdeslam, Salah’s brother, also spent time in prison with Abaaoud.³⁶ He would go on to be one of the terrorists in the Paris attacks. Khalid and Ibrahim El Bakraoui, both suicide bombers in the Brussels attacks, had served lengthy prison sentences for armed robbery and assault on police.³⁷

The marginalization of European Muslims and its role in jihadist radicalization is likely to be exacerbated by anti-Muslim and anti-immigrant feeling in Europe. Anti-immigrant, ultranationalist and anti-Muslim parties once played a marginal role in European politics. Although Emmanuel Macron defeated Marine Le Pen, the leader of France’s ultranationalist National Front (now called National Rally), in the French presidential election, Le Pen made it to the runoff with the second strongest showing in the first round race. Far-right parties also have expanded their power in Germany, the Czech Republic, Austria, the Netherlands, Italy and Poland, while left-wing parties have collapsed and center-right parties have moved rightward on immigration.³⁸

In April 2018, anti-immigrant nationalist Viktor Orbán was reelected as prime minister in Hungary with overwhelming support.³⁹ Orbán’s government proceeded to criminalize providing assistance to undocumented migrants.⁴⁰ Before the election, Orbán called for a global anti-migrant alliance and stated, “Christianity is Europe’s last hope,” warning that with mass migration “our worst nightmares can come true. The West falls as it fails to see Europe being overrun.”⁴¹

Meanwhile, Denmark’s government proposed new laws, to be voted upon in the fall, that would radically restrict the behavior of people living in ghettoized neighborhoods that are predominantly Muslim; they include doubling the sentences for certain crimes committed in the listed neighborhoods and criminalizing taking children on extended trips to their countries of origin that could damage their “schooling, language and well-being.”⁴²

A wild card that may shape this dynamic is the willingness of President Trump to openly support nationalist and anti-immigrant European politics. Trump has retweeted tweets from the deputy leader of Britain First, a far-right hate group.⁴³ Steve Bannon, the former chief executive of Trump’s campaign and White House adviser, plans to develop a group to promote a right-wing alliance of figures like Orbán.⁴⁴ Sam Brownback, the Trump-appointed U.S. ambassador for international religious freedom, has reportedly pushed for more sympathetic treatment of Tommy Robinson, a founder of the far-right English Defense League who is facing charges of disrupting a trial, and suggested that the Trump administration might otherwise intervene in the case.⁴⁵ The impact of this new relationship between parts of the European far right and the Trump administration and its circles on the political fortunes of the far right is not clear, but it is a dynamic that must be watched.

As anti-immigrant parties and agendas gain strength, they risk escalating the sense of alienation among Europe’s already marginalized Muslim population, potentially contributing to further radicalization.In some cases anti-immigrant and anti-Muslim politics has been expressed through terrorism. In June 2018, France arrested 10 people suspected of plotting a terrorist attack against Muslims and who had acquired rifles, handguns and grenades.⁴⁶ On June 19, 2017, a 48-year-old man killed one person and injured 10 others in a vehicle ramming near a mosque in north London, targeting Muslims during Ramadan.⁴⁷ In 2017, Germany reported 950 anti-Muslim crimes with 33 injuries as a result of such crimes.⁴⁸ While this far-right violence poses a significant threat on its own, it should also raise concerns about the potential for homegrown cycles of violence driven by polarization in European politics.

Geographic Proximity

The fourth factor that results in Europe facing a more severe threat is that Europe is simply closer in geography to the parts of the world where revolution and war have opened opportunities for jihadist organizing, while the United States is separated from these areas by thousands of miles and two oceans. As a result, the repercussions of instability in the Middle East and North Africa have more impact on Europe than on the United States.

Corrected at 2:20pm on September 11, 2018: A previous version of this report left out the surnames of Salah Abdeslam and Ibrahim El Bakraoui.