User blog comment:PLR Soldier/New Trailer - Battlefield 4: Officials Single Player Story Trailer/@comment-79.33.129.165-20131022205649/@comment-4563909-20131022213514

Yeah, Changi Airport in Singapore. Singapore is a confirmed location, though there is no doubt that the tower scene at 1:00-1:02 is Milad Tower (in Tehran). There's even an F4 Phantom fighter jet present, which is used by Iranian Air Force. My guess is that it is Mehrabad International Airport. Has to be, seeing how unrealistically close Milad Tower is (in reality they are many miles apart).