The window of opportunity for a “two-state solution” to the Israeli-Palestinian conflict has long been narrowing. Should the Israeli prime minister, Binyamin Netanyahu, endorse the conclusions of the Levy report, he could close it for good. The report, produced by a government-appointed panel led by the former Supreme Court justice Edmund Levy, argues that Israel’s presence on the West Bank does not constitute an occupation and, therefore, that the 121 Jewish settlements in the region are legal under international law. The acceptance of the report by the Likud-led government would formalise the de facto annexation of the West Bank and make the creation of a viable Palestinian state impossible. Israel would then be forced either to grant full citizenship to its Arab population or, in the words of its former premier Ehud Olmert, “face a South African-style struggle for equal voting rights”.

Speaking in 2007, Mr Olmert presciently added: “The Jewish organisations, which were our power base in America, will be the first to come out against us because they will say they cannot support a state that does not support democracy and equal voting rights for all its residents.”

Many Jewish Americans, 78 per cent of whom voted for Barack Obama in 2008, are struggling to reconcile their historic support for Israel with their dismay at its disregard for liberal norms. In response to the Levy report, 40 Jewish Americans associated with the Israel Policy Forum, a centrist body founded in 1993 with the support of the then Israeli prime minister, Yitzhak Rabin, wrote to Mr Netanyahu warning him that, if endorsed, the report will “add fuel to those who seek to delegitimise Israel’s right to exist”.

Even if, as seems probable, Mr Netanyahu rejects the commission’s findings, the two-state solution remains imperilled. In defiance of the UN, the US and the EU, the Likud-led government has continued to expand Israeli settlements in the West Bank and East Jerusalem to the point where there are now more than 550,000 settlers there, controlling 42 per cent of the land and representing nearly 10 per cent of the Israeli Jewish population. With every new settlement that is constructed, the possibility of a viable and contiguous Palestinian state recedes further. It is in this context that an increasing number of figures on both sides have abandoned the principle of “two states for two peoples” in favour of that of one binational, secular state. In his review on page 40 of Peter Beinart’s book The Crisis of Zionism, which charts the former New Republic editor’s progressive disenchantment with Israel, Geoffrey Wheatcroft writes: “The settler and Palestinian populations are now so mixed up that a rational and fair partition is practically impossible.” In addition, as the Palestinian-American author Ali Abunimah points out on page 25, a recent poll found that 36 per cent of Israelis and 31 per cent of Palestinians support “one state for two people in which Arabs and Jews enjoy equality”.

Yet while the proposal of a one-state solution has consid­erable rhetorical appeal, it is no less fraught with difficulty. To suppose that Israelis and the Palestinians could live side by side in one state is to indulge in liberal utopianism. As Jonathan Freedland writes on page 22, “It suggests that two nations that could not negotiate a divorce should get married instead.” Most Israelis and Palestinians will continue to support a two-state solution as the means for both sides to preserve the right to national self-determination. There is no mandate for a one-state solution, whether it be a “greater Israel” or a binational state.

At least rhetorically, Mr Netanyahu has accepted as much. In 2009, he declared that he was willing to see the establishment of a Palestinian state, albeit one barred from having an army and controlling its airspace. Two factors in particular mean that he must now live up to his word. The first is what Mr Netanyahu once called “the demographic threat”: the likelihood that the number of Arabs in Israel and the occupied territories will exceed the number of Jews in the next two decades. Should this landmark be reached with a Palestinian state still unestablished, Israel’s discrimination against its Arab population will be the subject of even greater outrage. The second is the Arab spring and the potential for it to undercut Israel’s status as a bulwark of multiparty democracy in the region.

If Israel is to achieve the two-state solution that its ultimate security depends on, the expansionist settlement programme must be reversed and Mr Netanyahu must negotiate with the Palestinians – who have not been well served by their own leaders over many years – in something approaching good faith.