Heavy area music Nice!
It's sounds epic, but not too serious or desperate =D
As to what scenario it belongs to in my opinion: I think this song fits best in the scene from House of 1000 Cats. So it's not a military base per se, but certainly something highly secured.
you know what, I think I'll give this a shot as Tank music in Left4Dead! ;)
That may be the creepy atmosphere you're talking about ^^