As the truce appeared to largely hold, a deal appeared far away in Gaza, where an Israeli strike killed dozens, according to a rescue group.

Back then, Syrian rebels were closing in on the regime’s strongholds, even as Assad leaned heavily on Iran and Hezbollah for support in the years prior. Moscow’s intervention turned the tide, culminating in the recapture of the largest Syrian city of Aleppo and a fragile stability that has largely held since.