The ISIS attacks in Brussels and Paris have raised concerns about the threat posed by returning Western “foreign fighters” from the conflicts in Syria and Iraq who have been trained by ISIS or other jihadist groups there.
One of the Brussels bombers, Ibrahim El Bakraoui, had been detained in Turkey and sent back to Belgium. He was believed to be planning to join ISIS in Syria.
Seven of the attackers in Paris were European nationals who had trained with ISIS in Syria.
Yet in the United States, the threat from returning foreign fighters remains quite limited. According to FBI Director James Comey, 250 Americans have gone or attempted to go to Syria. This figure is far fewer than the estimated 6,900 who have traveled or attempted to travel to Syria from Western nations as a whole — mostly from Europe.
As many as 1,900 of those militants have returned, according to an estimate by the U.S. House Committee on Homeland Security.
In a report released Friday, New America identified 94 American militants who have traveled to Syria, attempted to travel to Syria or provided support for those who did. Of those, 71% were arrested before reaching Syria. Twenty-seven managed to reach Syria and join a militant group.
For example, Shannon Conley, a 19-year-old woman from Colorado, pleaded guilty in September 2014 to attempting to provide material support to ISIS. She never set foot in Syria, as she was arrested at the Denver International Airport.
Of the 27 who joined militant groups in Syria, 12 are dead. Douglas McAuthur McCain, for instance, a Muslim convert from California, was killed fighting for ISIS in a battle against the Free Syrian Army.
Six Americans returning from Syria have been arrested. Among them was Mohamad Saeed Kodaimati of California, who pleaded guilty in October to claiming falsely he had not joined al Nusra Front, the Syrian al Qaeda affiliate, after he traveled to Syria in 2012.
Of the six known American returnees from Syria who are in U.S. custody, only one is alleged to have plotted an attack inside the United States.
Court documents allege that Abdirahman Sheik Mohamud, a 23-year-old from Ohio, left to fight in Syria in April 2014 before returning to the United States two months later. After his return to the United States, he was monitored by an informant, leading to his arrest. Mohamud has pleaded not guilty to plotting an attack on a U.S. military base.
Floridian Moner Abu Salha managed to travel to Syria and train with al Nusra before returning undetected to the United States in 2013. Rather than preparing a U.S. attack, Abu Salha returned to Syria after unsuccessfully trying to recruit a few friends to join him, and died conducting a suicide bombing against the troops of Syrian leader Bashar al-Assad.
Interestingly, several of the cases of American militants training in Syria and returning do not involve ISIS. Instead a number of the American returnees such as Abu Salha were affiliated with al-Qaeda affiliate al Nusra.
So far, the cases of Americans returning from Syria also do not indicate a threat anywhere near as severe to that in Europe.
Meanwhile, the United States wrestles with the far more likely threat from extremists inspired by ISIS but not trained by them. In San Bernardino, California, in December, a married couple attacked office workers attending a holiday party, killing 14. It was the most deadly terrorist attack in the States since 9/11. Syed Rizwan Farook, a U.S. citizen, and his wife, Tashfeen Malik, a legal resident, carried out the attacks. Malik pledged allegiance to ISIS on a Facebook account shortly after they had carried out their massacre.
The United States will have to continue to be vigilant regarding the potential threat from American returnees, but the most lethal threat is not from ISIS-trained militants launching attacks in the States but rather ISIS-inspired attacks. Such ISIS-inspired attacks rarely attain the lethality of the attacks by ISIS in Brussels and Paris.