The Gatekeepers is a very complete and politically insightful documentary. It comprises interviews with the six surviving former heads of Shin Bet, the Israeli internal security organization, since the war of 1967. Whilst Mossed is notorious for tracking down state enemies abroad, Shin Bet is the equivalent of MI5, its remit to monitor and prevent terrorism within Israel's contested borders. Whilst less well-known outside Israel, its role is arguably more pivotal to the contemporary Zionist state.

What is remarkable about the film is that, through the reminiscences of these men, Israeli political history is drawn into such sharp, unpartisan perspective. These are men who have overseen military-style operations against the Palestinians during the key moments of Israel's troubled recent history, from the initial occupation of the West Bank and Gaza in 1967 through to the first intifada in 1987, the Oslo accords in 1993, the assassination of Prime Minister Yitzhak Rabin in 1995, and the growth of suicide bombers targeting Israeli cities. And whilst there is no sense that any of the six questioned either the methods or tactics of their role in defending the Israeli state and people, including the use of torture and bombing raids which killed innocent people, retirement has given them the freedom to reflect on the apparently intractable Palestinian issue.

Director Dror Moreh is a quiet presence throughout, but his questions skilfully encourage each man to discuss not only the human cost to both sides, but also the wider political reality of Israel's presence in the occupied territories, and the parallels with other occupying countries throughout history. At the same time, the film retains a tight-lipped, business-like approach throughout, a tone set by its subjects. There is no sentimentality here, which makes the political conclusions drawn all the more powerful. And when some of the most powerful men of the Israeli establishment call for a fundamental shift in Israeli policy towards the Palestinians, and at points bemoan right wing forces within Israel that have exacerbated the problem, the effect is both sobering and quietly dramatic.