Three of the nation's top counter-terror officials told a House hearing Wednesday that they have no information that ISIS is plotting attacks in the U.S. But concern remains high that Americans and Europeans who have gone to Syria will seek to return to their home countries and carry out violent attacks.
Asked how confident they are that the U.S. knows which Americans have gone to Syria to join a terror group, FBI Director James Comey said that the U.S. uses "human and technical sources" to identify them. "It's very difficult," he said. "I'm not overconfident."
Homeland Security Secretary Jeh Johnson said "we have a reasonable degree, not a high degree, of confidence that we know who has attempted to travel there." Responding to recent news reports, Johnson said he has seen no indication that ISIS is trying to sneak into the U.S. across the border with Mexico.
U.S. officials have repeatedly said that more than 100 Americans and 2,000 Europeans have gone to Syria. As for the Americans, Matt Olsen, director of the National Counter Terrorism Center, said the 100 number represents those "who have traveled to Syria or attempted to" go there. Once in Syria, he said, it's hard to know what they do. "With varying degrees, we have specific information about who they are."
The officials said they're concerned that the increase in the number of terror groups is leading to global competition about who can be the most dangerous.
"These groups are in competition with one another for attention, fundraising, and recruitment. And one way to compete is to show that you're the biggest and baddest group out there," Johnson said.
Comey agreed. "The logic is compelling," he said. "You're not going to be the leader of the global jihad without striking America."
Core al Qaeda, seeking to reassert itself, recently announced it has a new affiliate in the Indian subcontinent, Olsen said.
All three said ISIS has become especially adept at using the Internet and social media to recruit, but Olsen said it's too soon to know how effective it has been.