Alarmed about the growing threat from Islamic State, the Obama administration has dramatically stepped up warnings of potential terrorist attacks on American soil after several years of relative calm.
Behind the scenes, U.S. authorities have raised defenses at U.S. military bases, put local police forces on alert and increased surveillance at the nation’s airports, railroads, shopping malls, energy plants and other potential targets.
Driving the unease are FBI arrests of at least 30 Americans on terrorism-related charges this year in an array of “lone wolf” plots, none successful, but nearly all purportedly inspired by Islamic State propaganda or appeals.
The group’s leader, Abu Bakr Baghdadi, drove home the danger in a 34-minute audio recording released online Thursday. He urged Muslims everywhere to “migrate to the Islamic State or fight in his land, wherever that may be.”
The audio was released with translations in English, French, German, Russian and Turkish, signaling the terrorists’ increasingly ambitious attempts to draw new recruits and to spark violence around the world.
U.S. officials estimate the Sunni Muslim group has drawn 22,000 foreign fighters to Syria and Iraq, including about 3,700 from Western nations. About 180 Americans have gone or have tried to go.
U.S. counterterrorism officials initially viewed Islamic State as primarily a regional security threat, focused on expanding and protecting its self-proclaimed Islamist caliphate in Syria and Iraq, rather than launching attacks abroad.
But the analysis has shifted sharply as terrorists inspired by the group, but not controlled or assisted by them, opened fire at the Parliament in Ottawa; at a cafe in Sydney, Australia; at a kosher grocery in Paris; and, on May 3, in Garland, Texas.