The United States has attacked three sites in Iran, inserting itself into Israel’s war aimed at destroying the country’s nuclear program in a risky gambit to weaken a longtime foe that prompted fears of a wider regional conflict.

It remained to be seen whether the attack would ignite a regional war or provide the U.S. and Iran with an off-ramp from their intensifying confrontation.

A U.S.-brokered ceasefire brings a possible end to the 12-day Israel-Iran conflict, but tensions linger as evacuation alerts, air raid sirens, and uncertainty continue to grip the region.