 FACT: As the Alien Destroyers enter the Earths atmosphere, one  scene cuts to a surfaced submarine in the Persian Gulf. It  identifies the submarine as an SSBN in the Persian Gulf. This is an  indicator of a Ballistic Missile Submarine. 1) SSBNs do not cruise  on the surface in hostile waters, they are only on the surface when  entering, tied up or leaving a friendly base. They submerge and  disappear. 2) SSBNs operate in the safety of the deep. The Persian  Gulf is not deep enough for an SSBN to safely operate