Turkey needs Russian cash, gas and business as Erdogan looks to a dicey election and a new incursion in Syria, while Moscow needs friends to try to evade Western sanctions.
After 11 years of war, Syria has become a cautionary example of what can happen in a conflict with no end in sight, like the one that began 100 days ago in Ukraine.
President Recep Tayyip Erdogan says Turkey will build homes, schools, hospitals and more in northern Syria, but experts question whether refugees will return willingly.