TERRORISTS TAKING OVER an office building. Terrorists taking over a luxury liner. Or an airplane, or Air Force One, or the Eiffel Tower or the Goodyear blimp.In the past few decades, Hollywood discovered that terrorists make easy villains: cunning, ruthless and immediately hiss-able. Ever since Nazis and Cold War Commies lost their shock value, films and TV have embraced terrorists as the faceless baddies that could be thwarted by Bruce Willis, Arnold Schwarzenegger, Steven Seagal, or the special terrorist unit. Audiences have come to enjoy cartoon-like terrorists; explosions and destruction are guaranteed entertainment. But the Sept. 11 tragedy was a shocking reminder: Terrorists aren’t fun. Destruction isn’t exciting to watch in real life. The scrambling of the networks and studios in the past few days serves as a reminder of how prevalent such depictions are: The webs have reskedded airings of “Independence Day,” “The Peacemaker” and “Under Siege 2,” while studios postponed the launches of feature films as diverse as “Collateral Damage” and “Big Trouble.” On the Web site Internet Movie DataBase, you can enter the category of “plots” and find 270 matches for the word “terrorist.” It may seem odd to describe this as an Age of Innocence in films, but there was a kind of innocence in Hollywood’s depiction of terrorism. Such villains could be suave (e.g., Alan Rickman in “Die Hard”) or folksy and neighborly (Tim Robbins in “Arlington Road”), but mostly they were a slobbering and sadistic group who threatened mayhem, but would get blown away before any serious damage occurred, i.e., before any of the principal actors got killed. Of course, drama is not like reality. While we enjoy watching Scarlett O’Hara, Charles Foster Kane, Lucy Ricardo and Austin Powers, we probably would find them insufferable in real life. But art and reality overlap, and on Tuesday, even the most sophisticated person couldn’t resist the feeling: This looks like a movie. That jet flying into the World Trade Center looked like a skillful CGI effect. Certainly, the cumulative effect of films and TV had deadened our reaction to the concept of terrorism. But after the 1993 World Trade Center attack, the Oklahoma City debacle and now this week’s tragedy, will there be a different cumulative effect, will we eventually cease to see explosions as fun? This is a young country. Compared to most other nations, America is like a teenager. We watched movies about bombings and, like teenagers, we felt indestructible: Deep down, we knew that bad things happened only to other people. America was founded on violence; while we see the Revolutionary War as a fight for independence, the British viewed it as acts of colonial terrorism. Americans love any movie in which the hero or heroine kicks butt. So maybe it will be cathartic to see terrorists get knocked around. But maybe not. During World War II, Hollywood became a key cog in the propaganda machine, cranking out films that informed viewers, promoted the government stance and, crucially, that reflected the mood of the times. But the film biz sat out the Vietnam war until years after the fighting had stopped. That was a TV war, and during the late ’60s and early ’70s, Americans didn’t want dramatic depictions of the war that they didn’t like or understand. Many consider America to be at war with the so-far-unnamed terrorists. It’s too early to say whether Hollywood will embrace this war, or shy away from it. But either way, will we ever return to an Age of Innocence? And do we want to?