In the notoriously fluid Syrian conflict, a host of rebel groups are fighting the government and competing for resources, forming and dissolving tactical alliances but rarely making major gains. Against this fractured backdrop, though, a new name — the Army of Conquest — has emerged...

Nearly 30,000 people, including more than 250 Americans, have left their countries to join militant Islamists fighting in Syria and Iraq, many with the Islamic State, according to a congressional study of the issue released on Tuesday. The six-month study by Republicans and Democrats on...

When an explosion killed almost all of its leaders in a single blow last year, many thought it was the end for Ahrar al-Sham, a powerful Syrian insurgent group founded by members loyal to al Qaeda. But the group immediately re-emerged stronger. It replaced its leader and chose new...

Afghanistan said on Wednesday that Mullah Omar, the elusive leader of the Taliban movement fighting to topple the government, died more than two years ago. The announcement came a day or so before a second round of peace talks had been tentatively scheduled, and news of the fate of the...