Agencies remain uncertain about the danger that the militant group poses to the United States.
13 years after 9/11, U.S. operations rage on against terrorist groups in Pakistan, Somalia and Yemen.
Journalist Steven Sotloff was kidnapped in 2013 and was being held by the Islamic State.
Reliable information and drones would be limited in an offensive in Syria against radical Islamist group.
Senior White House officials meeting on purported beheading of American journalist James Foley.
The Yemeni government has given over $1 million to the families of the dead and injured, documents show.
Efforts are considered evidence of group’s intent to carry out terrorist plots against U.S., officials say.
Obama administration’s response has mostly consisted of limiting U.S. military’s intervention.
The militants abandoning al-Qaeda affiliates to join the rival group are a sign of its appeal, U.S. officials say.
Release of document is delayed as chairman of intelligence panel raises objections with the White House.