Reading Matt Eckel's take on Stephen Walt's "unsettling question" regarding the two-state solution, you come away with these options for the future of Israel:
1. The two-state solution,
2. The one-state solution,
3. Israel as a permanent apartheid state, or
4. Ethnic cleansing of the Palestinians
I rank those by their level of horror, from lowest to highest. They are not ranked by probability of occurrence, where #3 seems considerably more likely than any other possible outcome (though some in Israel would be fine with #4) especially given the result of the recent elections.