The convoy of U.S. armored vehicles headed east, Stars and Stripes flapping in the wind as it lumbered toward its apparent destination — the oil fields of Rumeilan, in Syria’s far northeast.

There, pump jacks line both sides of the road, churning up and down. Smoke from small refineries rises into the sky and fires shoot from natural gas outlets. Electrical lines dot the landscape and tankers plod up and down the pothole-racked highway.