The head of the House Homeland Security Committee on Wednesday said extremist groups like the Islamic State in Iraq and Syria (ISIS) must be regarded as “armies."
Extremism inspired by the terrorist organization is “spreading like wildfire around the globe,” Rep. Michael McCaul (R-Texas) said in his opening statement during a panel hearing on the threat.
He added that its "ability to match words with deeds is growing at an astonishing rate … we are talking about terrorist armies.”
"We must keep these barbaric terrorists out of the homeland to protect the American people,” McCaul added.
Administration officials estimate that foreign fighters are flowing into Syria and Iraq at an “unprecedented” rate to join ISIS and other terror groups like al Qaeda.
Some 20,000 individuals from around the world, including at least 3,400 from Western nations have traveled to join the extremists, according to prepared testimony by Nick Rasmussen, chief of the National Counterterrorism Center.
The administration estimates over 150 individuals from the U.S. have also trekked to the conflict zone.
“The rate of foreign fighter travel to Syria is unprecedented. It exceeds the rate of travelers who went to Afghanistan and Pakistan, Iraq, Yemen, or Somalia at any point in the last 20 years,” Rasmussen said.
McCaul said the figures make “this the largest convergence of Islamist terrorists in world history.”
He rattled off a list of recent security incidents that show calls by ISIS for Westerners to “wage individual jihad” in their home countries is “working,” the list including a foiled attempt by an Ohioan to attack the U.S. Capitol.
“I am worried about our ability to combat this threat abroad, but also here at home,” McCaul said.
The administration said it was unaware of any direct threats to the U.S. but "increased vigilance" is needed in light of recent attacks elsewhere, according to Francis Taylor, undersecretary for intelligence and analysis at the Homeland Security Department.
The “terror threat is dynamic,” he said.