It might seem like an all-too familiar story: With its economy cratered by civil war, and new pockets of anti-regime resistance, Syria is on the verge of state collapse. President Bashar al-Assad isn’t just on the back foot; he is weaker than ever. Is he about to fall?

BAGHDAD—The Islamic State is stepping up its attacks in Iraq, fulfilling the expectations of many analysts that the extremist group would mount a comeback after the Iraqi government declared victory over it in 2017.

Imagine a different Middle East. “Were all outstanding hostilities resolved, border formalities simplified and roads unblocked, one might breakfast beside the Mediterranean in the Lebanese capital of Beirut, drive up to the Syrian capital of Damascus for lunch, race south to Jordan’s Amman for tea, make Jerusalem for an early …