TWO months ago Heftsiba, an Israeli construction firm, went bust. One reason for its woes was a court order last year to freeze work on a big housing project on an Israeli settlement just inside the West Bank. The land, it turned out, had in effect been stolen from private owners in a neighbouring Palestinian village, Bilin. Yet after the bankruptcy, the same court ruled that the apartment blocks—and their prospective buyers, who had broken in and occupied them at the news of Heftsiba's impending collapse—could stay.

And thus it has always been. Never mind that Israel has flouted international law by settling its citizens in occupied foreign territory; what is remarkable is how consistently the settlers have thwarted Israel's own laws, in pursuit of what to them are biblical lands inhabited by Palestinian interlopers. The Bilin case was just a variation on a tried and tested method: seize land illegally, establish hard-to-reverse “facts on the ground” and then legalise the claim retroactively through the courts or the government. The result is a West Bank so riddled with settlement that it is hard to see how enough can be removed for a viable Palestinian state to emerge.

In this thorough and eye-opening book, Idith Zertal, a historian, and Akiva Eldar, a journalist, explain how a few tens of thousands of people bent the state to their purpose. Settlements were not on the official agenda after Israel's surprise capture of the Palestinian territories in 1967. But pressure from ardent young religious Zionists found a secular echo among military men, who came to see security benefits to having Israelis live in the West Bank.

Such confluences of interests were what drove the settlements' spread. Only rarely, when a new outpost was too blatantly illegal and too plainly of no strategic use, did the apparatus of the state contrive to force a retreat. With politicians constantly interfering on behalf of the settlers, the army's effectiveness against law-breakers soon bled away.

Over the years, official attitudes evolved. The Labour governments that ruled until 1977 turned a blind eye to expropriations of land for “military” use that then became civilian. The more right-wing coalitions that followed embraced settlements openly, devising ingenious legal veneers. Since the 1993 and 1995 Oslo accords, Israel has avoided building “new” settlements via administrative tricks that expanded existing ones, though it has also ignored innumerable violations. Whatever the government in power, the settlers' genius was in exploiting its weaknesses and co-opting sympathetic officials.

The authors' anger falls mainly on the religious pioneers and their secular allies, especially Ariel Sharon, whose removal of settlements from Gaza in 2005 was, they argue, no more than a way to consolidate the hold on the West Bank. But nobody escapes blame. Shimon Peres, Israel's elder statesman, emerges as one of the settlers' most useful early helpmates. Yasser Arafat, the Palestinians' former leader, and Mahmoud Abbas, their current president, were still exiles in Tunis when they negotiated the first Oslo accord and had no idea how settlements had permeated the West Bank. To the horror of their local advisers, they agreed to no more than a token constraint on settlement growth. Yitzhak Rabin, the prime minister who signed Oslo and whom the authors plainly admire for hating settlers almost as much as they do, gets a lashing for presiding during one of their fastest rates of growth and being in a “state of denial” about their influence.

That denial had much to do with an inability to grasp how different religious Zionism, with its messianic belief that Israel's creation hastened Redemption, was to Rabin's traditional, secular-nationalist sort. For the true believers, constant war with the Arabs was essential to avoid “assimilation [of Jews] into the Semitic expanse”. The costs of this ideology to Israel, let alone the Palestinians, have been enormous. Rabin's assassin in 1995 was inspired by a settler, Baruch Goldstein, who killed 29 Palestinians in a Hebron mosque in 1994. Goldstein's rampage, according to a former adviser to the head of Israel's security service, also prompted Hamas to begin the tactic of suicide-bombings against Israeli civilians.

And yet, the authors conclude, traditional Zionism must take a share in the blame. It was the aggressively secular early state of Israel that repressed religious Zionism in the first place, setting the stage for its violent revival, and for the dichotomy in Israel's nature that it has yet to resolve.