As Tony Judt wrote over a decade ago, the idea of a particularly Jewish homeland is rooted in nationalist ideology from the late 19th and early 20th century. This ideology that has been progressively discredited since that time. The modern nation-state often retains some nationalist flavor, but the standard basis of nations today today is citizenship defined through membership in national institutions, not ethnicity, religion, or race. "Israel, in short, is an anachronism," he put it. [...]

The major problem with Israel is the occupation of the West Bank and Gaza. It is a tyrannical domination of a subject population, the source of endless conflict, and arguably the greatest long-term threat to Israel's security (despite its military superiority). If the problem can't be resolved, the international animus it inspires will continue to fuel the pressure for boycotts and sanctions, and will someday probably lose Israel free access to America's United Nations Security Council veto.

In all the territory controlled by Israel, there are over 6.2 million Palestinian Arabs, and about 6.5 million Jews. The Israeli birthrate is high, but the Palestinian birthrate is higher. Someday soon, Arabs will outnumber Jews in Israeli-controlled territory.

This leads directly to the dilemma of liberal Zionists: If Israel wants to remain democratic, it can either divest itself of the occupied territories, and thus retain its Jewish majority, or it can become one single state that is half Jewish and half Arab. The former is all but impossible to imagine, given the total collapse of the peace process. The latter would mean abandoning the idea of a particularly Jewish nation.

If Israel continues the occupation without giving Palestinians full citizenship, it will have abandoned democracy. This seems the most likely outcome. Indeed, by most definitions of the term Israel has been a de facto apartheid state for decades now -- in the 2015 election campaign, Benjamin Netanyahu overtly promised that he would prevent the formation of a Palestinian state while he was prime minister. The demographic balance tipping to an Israeli minority would merely check one of the last boxes on the apartheid checklist.