Sha'fa, Syria (CNN) The drive down to the frontlines with ISIS is long and dangerous. Our escorts from the Kurdish-led forces insisted on taking us in armored vehicles from their base in the al-Omar oilfield. There are ISIS sleeper cells all around, they explained. They come out at night to plant roadside bombs.

For nearly three hours, we bumped through dusty abandoned villages. As you get closer to the frontlines, there is little to see but miles and miles of rubble.

We stop briefly in the town of Hajin. ISIS was pushed out weeks ago but there's no one here to celebrate. US coalition air power has obliterated much of the town. A handful of young fighters man a checkpoint in the rubble. For many of the people who lived in these areas, this is what liberation looks like.

Syrian Democratic Forces (SDF) troops take a break between the town of Sha'fa and Soussa, one of the last ISIS-controlled villages in southeast Syria.

This vast swath of desert along the Iraq border has long been insurgent territory. During the war in Iraq, fighters with al Qaeda would regroup here before crossing back to continue fighting in Anbar province.

ISIS still draws sympathy and support from some around here. The US-allied Kurdish forces who liberated the area rule over an overwhelmingly Arab population, and they are seen by those who share ISIS's toxic ideology as murtadin, or apostates, who collaborate with the American crusader.

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