Character Analysis
Nimziki is the Secretary of Defense, and kind of the only non-alien antagonist the movie has. He does not give the President great advice during the alien crisis, recommending measures that are, at best, ineffective, and at worst, dangerous—for example, when he advocates a nuclear strike.
Meanwhile, he doesn't speak up when he could be helpful…like when he fails to let the President in on the secret that Area 51 is real, and the U.S. government has been housing alien corpses and an alien spaceship.
Sure, we get that Nimziki was trying to give the President plausible deniability, but once aliens surrounded earth and started attacking, that was probably the time to let the President know that the U.S. government had been studying alien physiology and technology for decades.
When Nimziki tries to advise the President against David Levinson's plan to give the alien spaceship a computer virus, the Prez finally decides he's gotten enough bad advice from Nimmy and fires him.
There's really nowhere for him to go at that point, though—you know, given the whole "aliens have destroyed most of our country" thing—so he ends up in Julius's prayer circle while David, Steve, the President, and a whole bunch of pilots organize and execute the final assault on the aliens.
Maybe he'll slip a little prayer for his own forgiveness in there while he's at it.