“Almost all the intelligence agencies in the world failed to foresee major historical events,” says Avi Dichter in Dror Moreh’s Oscar-nominated documentary The Gatekeepers. Dichter was the director of the Shin Bet, Israel’s intelligence and security service, from 2000 to 2005, and his statement comes across more as a fact than an excuse. In the film, the other five surviving former heads of the Shin Bet join him, explaining in separate interviews the challenges of the job, the seemingly never-ending violence they tried to combat, and the reasons for some of their questionable or altogether shocking decisions.

Some of their attitudes might be shocking, too. Avraham Shalom (shown), director from 1981 to 1986, is now a sweet-looking, slightly hunched elderly man. But you discover about midway through the film that people once feared him; another head calls him “a bully.” He resigned quickly during the investigation of a scandal regarding the 1984 hijacking of what is known as Bus 300, which involved four Arab terrorists from Gaza taking control of a Tel Aviv bus. Under Shalom’s orders, two of the eventually captured terrorists were executed, even though their hands had been tied and they seemingly no longer posed a threat. Shalom tried to cover up his actions and now unapologetically tells Moreh that if a reporter hadn’t been around, no one would have known. Suddenly he doesn’t seem so sweet.

Like a typical documentarian, Moreh uses a combination of commentary from the directors, archival footage, and photographs—-many graphic, showing the dead or bloodied victims of acts of terror—-as well as haunting music to mold his narrative. The presented history of Israel’s political instability goes back to the Six-Day War of 1967 and continues to the present, with the heads touching on everything from the brutal interrogation techniques they were allowed to use to specific incidents (such as the assassination of Prime Minister Yitzhak Rabin) to the fresher difficulties of trying to get information from current terrorists and suicide bombers of Hamas (“Anyone willing to sacrifice his life, whether it’s for the virgins in paradise or not, has nothing to lose”).

It’s all fascinating stuff, the equivalent of getting inside information from the FBI or CIA, though some of the finer details of the topics discussed may be difficult to grasp by viewers not intimate with Israeli/Palestinian history. Moreh’s achievement in that regard, coaxing all six directors to open up about secure matters, is extraordinary—-but he’s not content to just let his subjects tell the stories as they please. At one point during the discussion of the Bus 300 incident, Moreh asks Shalom about the morality of what the Shin Bet did. He seems exasperated by the question. “With terrorism there are no morals,” Shalom responds. “Find morals in terrorists first.”