/With End of Islamic State Caliphate, U.S. Shifts to Long New Fight Ahead

With End of Islamic State Caliphate, U.S. Shifts to Long New Fight Ahead

WASHINGTON—The final defeat of the Islamic State extremist group’s self-declared caliphate marked an important battlefield victory in the fight against the terrorist network, but it also signaled a shift to a more difficult fight to come, U.S. military officials and experts said.

For U.S. counterterrorism strategy, the focus will move from years of armed conflict as the group held parts of Iraq and Syria to confrontation with a more dispersed and furtive insurgency, officials and analysts said. It also will mean devising ways…