While the movie included some pretty good names in the cast, including Lewis Gossett, Jr. and Malcolm McDowell, the plot was pretty standard and predictable.

After all of the calendars rolled over to Jan 1, 2000, there was one clock that didn't quite roll over correctly.  Forgotten many years ago, a biological warhead atop a intercontinental missile surrounded by a unbreakable security system, rolled all right -- rolled around to Jan 1, 1964.  All of the security disarm codes are now invalid because they have start dates way in the future.

This missile system was designed as a counter-strike in case the US was annihilated in war.  So when it dropped contact with NORAD, the missile arms itself and starts it's countdown.

Interesting premise, too bad the movie was predictable following.  Military strike team. Underage hacker.  Disgruntled turncoat.  Last minute disarm.  Big explosion.  Etc, Etc.