The aftermath of a IED explosion in Beirut.
Credit: Reuters

Terrorist attacks worldwide surged by more than a third and fatalities soared by 81 percent in 2014, a year that also saw Islamic State eclipse al Qaeda as the leading jihadist militant group, the U.S. State Department said on Friday.

In its annual report on terrorism, the department also charts an unprecedented flow of foreign fighters to Syria, often lured by Islamic State’s use of social media and drawn from diverse social backgrounds.

Taken together, the trends point to a sobering challenge from militant groups worldwide to the United States and its allies despite severe blows inflicted on al Qaeda, author of the Sept. 11, 2001 attacks in Washington and New York.

Al Qaeda’s leaders “appeared to lose momentum as the self-styled leader of a global movement in the face of ISIL’s rapid expansion and proclamation of a Caliphate,” the report said, using an alternate acronym for Islamic State.

Last June, Islamic State attacked from its base […]