Rojava: the gate of middle-east 

On February 24, the US’s top commander in the Middle East, General Joseph Votel, visited Syria’s Kurdish city of Kobanê and pledged increased military support for the Kurdish-led Syrian Democratic Forces (SDF), including the US’s own direct involvement. After his visit, the Pentagon released its revised strategy to defeat IS in Syria, commissioned by the Trump administration. It sets out a plan to seize the de facto IS capital city of Raqqa, hingeing on strategic and material US support for Syrian and Kurdish forces on the ground.
The plan puts an end to speculation over which ally the US would choose, and implies that the Kurds might yet enjoy long-term American support for their Syrian battles. It also signals that a new, previously inconceivable geopolitical alignment is taking shape. So what made the US take the Kurdish side?