Airlines across Asia are diverting flights away from Iranian airspace after the US Federal Aviation Administration responded to Tehran’s missile attack on US-led forces in Iraq by banning American airlines from operating in the region.The Asian airlines now avoiding the airspace over Iran include Singapore Airlines, Malaysia Airlines and Singaporean low-cost carrier Scoot. Cathay Pacific said it had not flown over Iran and Iraq for “over a year” and AirAsia said it did not fly over the two…