“ISIL, through its actions and communications, has amplified al Qaeda’s message of war on the West to inspire a broader audience. That message will continue to spread and fuel instability in regional conflicts. Still, neither al Qaeda nor ISIL has achieved more than limited success in persuading Americans to sign up for their version of jihad. The terrorist organizations have not been able to build a deep reservoir of support here. There have been few terrorist plots, and as yet no mass exodus of U.S. volunteers going to Syria.
The most likely threat to U.S. homeland security will come from homegrown terrorists carrying out unsophisticated but lethal attacks. More ambitious plots also cannot be ruled out, although domestic intelligence efforts have been remarkably successful at preventing them. The terrorist assaults in January in Paris and this month at the museum in Tunisia, along with the seemingly endless string of non-terrorist shootings in the United States, are a potent reminder that it only takes a lone gunman — or two or three — to cause significant casualties.”
