it be infer by a previous poster that the military would not be subordinate to the police in a disaster a depict in the film . in fact the military role would be to supply aid to the civil authority when request to do so . the civil authority would retain primacy . in practise the army would need 48 hour or so to mobilise themselves and there not be much army presence in london and especially with current overseas commitment . even then they would be dependent on call in the ta . a for cobra and we be give the impression that it be a full governmental emergency department in it own right even reference to a met police cobra division . in fact cobra stand for cabinet office briefing room a. it just the room where the pm or dpm meet their adviser to discuss the current emergency .