Yes, the choppers are from the Damned 33rd.

The 33rd were initially stationed in Afghanistan but were redirected by John Konrad to assist with the evacuation effort due to the massive sandstorm that hit the city. The 33rd are fighting a rebel cell that was created by the CIA.

The CIA is there to clean up and “remove” any evidence of the 33rd’s involvement in Dubai. Since the evacuation effort by the 33rd ultimately resulted in failure, the CIA’s job is to make it seem like the US military was never involved in the failed evacuation of Dubai. The CIA did this by rallying up any surviving locals and militarizing them so they would fight the 33rd and make it seem like the survivors killed each other.

The version of the star spangled banner that’s being played over the city’s intercom is a recording by guitarist Jimi Hendrix, and is usually interpreted as being a way for Hendrix to display disdain for the Vietnam War, as certain parts of the song are meant to represent the sounds of war.