Funny story about the tanks
One of the producers of this movie also produced "Alien vs Predator: Requiem" and he tells a funny story on that movie's commentary (near the end when they're going into the hospital).
To paraphrase, he said the U.S. Department of Defense wouldn't let them use their tanks because they deemed the "Courage Under Fire" script too anti-military, so the producer was going around trying to find tanks for the movie. He found a state that had tanks (one of the southern states) and he met with the governor...
GOVERNOR: I'll let you use the tanks.
PRODUCER: Okay.
GOVERNOR: I've got a daughter, and she's an actress...
PRODUCER: Okay, we can find her a part in the movie.
GOVERNOR: I hear the lead female part is pretty nice.
The producer ends with saying they got the tanks from Australia.