If Satan and his demons took over earth...?

And God and his angels were nowhere to be seen, just demons monsters and fire across the earth. Horrible creatures killing and slaughtering humans in the thousands. What would the U.S. Military do? because this IS something Christians believe could happen. So lets take their religious idea literally for a second and wonder, what would the U.S. Military do? would marines be fighting demons? would the air force be used against flying demons? would the military try to evacuate civilians from cities?