The big plot driver was a Pentagon plan to create an EVIL weapon that could be used to assassinate individuals. How evil? Well, one Pentagon guy opposes it and another orders him murdered. To rub it in the planned test of the weapon is on a copy of JFK's Dallas motorcade.
Of course, if you replace the laser invented by our unwitting heroes with a Hellfire missile, and the B-1 platform with a Predator drone, you have the main instrument of our current defense policy. Yet no one's trying to fill the White House with popcorn.