I spent part of my Independence Day watching the movie Independence Day (1996) on Fox Television, and all I could think was how much the world has changed in the past eight years. Would that all we Americans had to worry about was an invasion by space aliens! But that was the way it was during the 1990s. The Soviet Union had crashed, the economy percolated along on the nascent Internet boom. It was supposed to be the end of history.

But now, in 2004, as I watched the skyscrapers of New York City disentegrate downwards in the movie and the White House go up in a big boom, all I could think was: All these things actually happened. Or nearly all of them happened, except that the flight of heroes managed to crash one of the planes in the Pennsylvania woods so that it never reached the White House. The enemies that were an outright fantasy 1996 turned out to be all too real. They turned out to be human beings, human beings who knew how to mass-murder in exactly the same implacable, unpitying way that the space aliens in the movie did. And they’re still out there.

“Independence Day” isn’t a great movie, with mostly wooden acting–and didn’t Jeff Goldblum already do that good-scientist thing in “Jurassic Park”? My favorite character was actually the evil scientist, played by Brent Spiner, who, following the Dr. Frankenstein convention that all horror movies must follow, gets offed by one of his own creations. It’s amazing how genre-conventional a film “Independence Day” is. The president (Bill Pullman) is a good-looking, conscientous stick figure like Martin Sheen on “The West Wing.” The space ships are from “Star Wars.” The aliens all look like “The Alien”–as though Sigourney Weaver just popped them through her chest. When someone in the movie mentions Roswell, N.M., you know that all the stories about the downed space ship there in the tabloids and on “The X-Files” will all turn out to be real.You know that pretty Jasmine Dubrow (Vivica A. Fox), girlfriend of  Marine Capt. Steve Hiller (Will Smith), will be survive because she’s so spunky and she’s got her little son and her dog with her. Rule No. 637 of sci-fi horror movies: The dog never gets killed. And you know that Hiller himself will make it through alive because he’s so brave and cheeky that he volunteers to fly one of the aliens’ space ships.

But I liked “Independence Day.” I liked it because it recognized that evil is real. It turns upside down the sentimental-liberal notion, peddled in movies such as “Close Encounters of the Third Kind” and gestures such as that famous disk we shot into outer space during the 1970s with the naked man and woman and all the scientific equations on it, that aliens from outer space are gentle, highly enlightened wonks who just want to be friends with us earthlings. “Independence Day” disabuses us of such sentimental notions fast. Some smiling naifs who stand under one of the space ships waving their hands and shouting words of welcome are zapped into dust. “We want to live in peace with you,” the president in good-liberal style informs one of the aliens. “We want to kill you,” responds the alien. The president at first shies away from using nuclear weapons against the extraterrestial invaders–that could trigger a war, you know–then goes ahead and gives the order to nuke ’em. (The nukes turn out not to work, but I liked the gesture.) I cheered when Smith as Capt. Hiller opened the door of the alien fighter-craft he’s downed and boomed “Welcome to Earth!” at the giant insect/pilot inside–and when he led his attack shouting, “Let’s go get E.T.!”

In short, what “Independence Day” tells us is that not all sentient beings out there are fundamentally good at heart and would love us instead of wanting to kill us if we only gave them half a chance. That’s a good lesson for Americans to keep in mind in the vastly changed geopolitical scene that followed Sept. 11, 2001. “Independence Day” is a movie about liberals mugged by reality. It’s about the grim fact that war is sometimes the only solution against an enemy hell-bent on exterminating us.