Tensions are mounting between two US backed military forces on the ground in Iraq. Iraqi military forces assaulted an oil field in Kurdish-controlled Kirkuk. This further complicates the fight against the Islamic State (Isis). The Iran-backed militia and the Kurdish forces have a common enemy in the Islamic State. And while the US supports both groups' mission to eradicate Isis in the Middle East, Kurdish military officials claimed Iran-backed militias armed with US equipment took part in the attack.