What a bittersweet moment it is near the end of “Eye in the Sky” when Alan Rickman delivers the perfect verbal takedown of someone who dares question his character’s judgment and experience.

I’m not going to reveal the line so as not to spoil the moment, but suffice to say it is classic Rickman, where he takes the longest beats, giving each word added power.

He will be missed.

The acting is world-class in “Eye in the Sky,” a timely and tense but sometimes heavy-handed drama set in the modern world of drone warfare, where soldiers in dark rooms thousand of miles removed from the actual targets make life-and-death decisions and push buttons that unleash deadly payloads — and then essentially punch out for the day and return home to their loved ones.

Even though “Eye in the Sky” is set in four continents and features some first-rate special effects, at heart it feels like a staged play.

Helen Mirren is the tough-as-nails British Col. Powell, who early one morning gets word of a possible sighting of a British-born woman who is married to a Somalian terrorist and has herself become a radical.

British intel says the terrorists are about to launch a suicide bombing attack in Nairobi. (The Brits are able to spy on the terrorists through a variety of high-tech devices, including a miniature camera hidden inside a realistic-looking bird, and an even tinier camera disguised as a flying insect.)

Powell wants to take out the terrorists’ lair before they strike — but the process of carrying out such a strike is so labored and convoluted and wrapped in red tape it would be comical if not for the high stakes involved.

Rickman’s Lt. Gen. Benson presides over a meeting of high-ranking British officials in London who must approve the use of force. Meanwhile, it’s the Americans who actually control the drones — from a U.S. Air Force base in Nevada. (Dramatic territory previously explored in the Ethan Hawke movie “Good Kill” last year.)

Aaron Paul from “Breaking Bad” is Steve Watts, an American pilot who does his job without ever leaving the ground. From his post at the installation base near Las Vegas, Watts works the controls of a Reaper drone equipped with two Hellfire missiles.

On first blush it would seem like an easy call. Obtain the necessary approval from the British higher-ups, zoom in on the target and let the Americans take out the terrorists before they murder dozens of innocent civilians.

But here’s the thing. There’s a 9-year-old girl selling bread on the street adjacent to the terrorists’ lair, and she will almost certainly be killed if the missiles strike that house.

Barkhad Abdi (the Oscar-nominated actor who played the pirate leader in “Captain Phillips”) is superb as the Brits’ mole in Kenya, who comes up with some ingenious and extremely dangerous ways to get the little girl out of danger. Meanwhile, Rickman’s Benson and Mirren’s Powell grow ever more frustrated with the bureaucrats and the American pilot who keep delaying the decision in the hopes the girl will be removed from the hot spot.

For the military, it’s a tough but clear-cut decision: You take out the terrorists and save maybe a hundred lives, and if one child is collateral damage, well, that’s tragic but it’s not as tragic as dozens of children being killed. For the man with his hands on the controls of that drone, it’s not so simple.

Director Gavin Hood, who helmed the 2006 best foreign language Film “Tsotsi,” keeps the tension level high, even with multiple scenes that are mostly about people talking on telephones or hunched over computers. The screenplay by Guy Hibbert is rich in strong dialogue but occasionally veers into manipulative melodrama, with lingering shots of that sweet, innocent little girl playing with her Hula Hoop and selling her bread, utterly oblivious to her possible fate.

As one would expect from this cast, the performances are as good as it gets. Mr. Rickman was never nominated for an Academy Award and it’s probably a long shot for a posthumous supporting actor for this film — but his work here is a reminder of what a special talent he possessed.

★★★

Bleecker Street Media presents a film directed by Gavin Hood and written by Guy Hibbert. Running time: 104 minutes. Rated R (for some violent images and language). Opens Friday at local theaters.