Even with the Islamic State on the run, U.S. advisers grapple with political and military problems in wresting Iraqi and Syrian towns from extremists.
Risky Special Operations missions targeting midlevel figures can prove valuable for unearthing information about the Islamic State’s inner circle.
Mr. Trump will take the stage in Saudi Arabia to deliver his centerpiece speech, aiming to reconcile his past rhetoric with his ambition of rebuilding relations with the Muslim world.
Defense Secretary Jim Mattis said President Trump’s decision to give the military more latitude had put greater pressure on militants in Syria, Yemen and Somalia.
The Pentagon is investigating the deaths of two Army Rangers during a raid targeting a leader of Islamic State militants in Afghanistan.