“Omar” opens Friday at Sundance Cinemas. Not rated, 1:38, three and a half stars out of four.

Somebody tells a story in “Omar” about how monkeys are caught in Africa. The (probably apocryphal) story goes that trappers dig small holes in the ground with narrow openings, and drop nuts that the monkeys really like into the holes. The monkey reaches in, grabs the nut, but then can’t pull its paw back through the opening without dropping the nut. So there the monkey sits, unwilling to drop the nut, as the hunters arrive at their leisure.

“Omar” is full of people like those monkeys, people so focused on what they want that they don’t see the danger that want places them in until it’s too late. The film was made by Palestinian director Hany Abu-Assad (“Paradise Now”), and is sadly wise about the hopelessness and frustration of life in Palestine. But at heart it resembles a Cold War thriller, with one protagonist caught between opposing forces, wondering who he can trust. The answer is nobody.

Adam Bakri plays Omar, a handsome young Palestinian baker who can easily scamper over the Israelis’ high security wall to visit his girlfriend Nadia (Leem Lubany) and his two best friends. Omar and his two friends dream of fighting the Israelis, and one night they take a rifle into the night and shoot an Israeli border guard.

Omar is captured and imprisoned for the fine, and an Isareli security officer (Waleed Zulaiter) offers him a deal — turn informant for the Israelis, and he can go free. Once outside, Omar attempts to play triple agent and betray the Israelis, but soon finds that neither side trusts him. Abu-Assad effectively builds an atmosphere of paranoia as Omar’s options become more and more limited, and he desperately tries to think of  a way out of his predicament.

The performances are all very naturalistic — Bakri makes Omar seem like a gentle soul, but also quick to anger under the constant injustices he feels at the hands of the Israelis. Zulaiter plays the Israeli agent with a sort of kindly menace, and we seem him trying to work his charm on Omar to get what he wants. The mental chess game between these two men is the heart of the film — who is outwitting who? — and makes “Omar” an engrossing thriller. Abu-Assad also keeps the pace fleet-footed, with lots of unexpected turns in the plot and some exciting action scenes, including two masterful foot chases through the narrow corridors and over the rooftops of the West Bank.

But all the genre trappings ultimately underscore that this is not a Cold War situation, a chess game between two equal opponents. It’s a lopsided struggle where even the smartest, kindness Palestinian can find himself dragged down by suspicion and betrayal.