The first impression one gets from the film “United 93,” which opens Friday, is that it’s predictably normal. Pilots and flight attendants go about routine business, from safety checks to making sure there is enough sugar for passengers. Conversations are about nothing consequential. This normalcy contrasts with the utter abnormality of 9/11 and it is what grips our stomachs, refusing to let go until long after the 111-minute film ends.

The debate about the movie started a few weeks ago when some people reacted strongly to the showing of the trailer at several New York City theaters. They claimed it was “too soon” to make such a film, though two others already have been shown on the A&E Television Network and the Discovery Channel, drawing 5.9 million and 7 million viewers respectively.

Director/writer Paul Greengrass (“The Bourne Supremacy” and “Bloody Sunday”) has created a profound and needed film that reminds us of what we must never forget: there are people who hate us and want us dead; they will not be reached by sympathy, empathy or anything approaching an appeal to our “common humanity.” Their complete indifference to human life and their religious fanaticism – portrayed powerfully as the hijackers pray and shave their bodies in preparation for “martyrdom” – is a necessary reality check for those with very short memories. If anything, this is a film that isn’t too soon; it isn’t soon enough.

There are no well-known actors in this movie, allowing us to focus on the real “star” – the heroism of the passengers. Their phone calls to people on the ground inform them two planes have already struck the World Trade Center and they conclude that people who want to strike another target have commandeered their flight. They concoct a plan to disable and disarm the hijackers, who had knives and what turned out to be a fake bomb. A passenger who has experience flying single-engine planes says he “thinks” he might be able to fly the jumbo jet if he can get to the controls. The plan is to overtake the hijackers, pull them from the cockpit and install the inexperienced pilot in the captain’s seat. Instead, the lead hijacker crashes the plane into a field in Shanksville, Pa.

Greengrass was fortunate to have had cooperation from many of the passengers’ family members. On a DVD provided by Universal Pictures, David Beamer, the father of Todd Beamer, who famously uttered the words “Let’s roll,” said: “This war and that attack on our homeland that day rages on and isn’t over. The enemy has not been defeated. The enemy has not surrendered. The enemy’s purpose to take away our freedoms and way of life is still very much with us. If this project helps remind us of this, it’s important and very timely.” David Beamer added, “This is part of our history. It is an accurate account of our first counterattack in this war.”

Elsa Gronlund Strong, sister of passenger Linda Gronlund, said: “Terrorism is unlike any other war and can’t be fought in the same way.”

None of the passengers is identified by name. There is no time for introductions. They not only share a sense of ultimate danger; they also share a sense of ultimate purpose. This is a value we like to think is, if not uniquely American, than a unique character trait of free people. These are Americans banding and bonding together in the sudden realization that they are part of an enormous event. There are no politicians leading them, no military officers commanding them. They more than rise to the occasion, they transcend it by doing the right thing and exemplifying true heroism.

Yes, the film is difficult to watch, but that should not be an excuse not to watch. Vivid pictures of the consequences of drug use, promiscuous sex, drinking and driving and other harmful behavior have long been used to cure apathy and to positively motivate. This film demonstrates the consequences of not being prepared and the wisdom of constant vigilance.

The show business publication Variety reported that studio tracking of “United 93” shows a high percentage of people are “definitely not interested” in seeing it, though by a slim margin, the picture is the top choice among males. It should be a top choice for everyone. “United 93” is a valuable weapon in our counterattack against terrorism. No American should miss it.

– Cal Thomas is a columnist for Tribune Media Services.