Leave aside whether this characterization is accurate and focus instead on why a realist – of all people – should care. The United States supports states with far more egregious human rights records than anything sketched above. A realist is supposed to give less weight to a state’s internal flaws and focus instead on its geopolitical orientation, right? ~Greg Scoblete
Prof. Walt can provide his own answer, but I would say that a realist wouldn’t worry as much about Israel’s “internal flaws” if they were simply internal. We have other allies that still occupy territory seized during wartime decades ago, but the rest of them are not client states to the same degree that Israel is and the rest of them do not receive such generous aid. It is because of the extent of the relationship and the complications it creates for the U.S. with most other countries in the region that the realist cares about the implications for U.S. interests if the two-state solution is indeed beyond saving.
It is also the realist’s concern that much of the rest of the world claims to see the resolution of this conflict as a high priority, and it is the realist’s concern that much of the rest of the world focuses, fairly or not, on Israel’s conduct in the occupied territories more than it does on the worse internal repressions of numerous dictatorships. My preference would be to acknowledge that both the Israeli-Palestinian conflict and the U.S.-Israel relationship are vastly less strategically important than most people claim that they are, but a realist has to work with the world as it is rather than how one would like it to be. In the world as it is, the conflict is seen as very significant for the entire region. In this world, an Israel that engages in mass expulsions or continues the domination of a subject people becomes an even greater political liability for the U.S. than it has been. The realist’s question would then become: is the relationship with Israel strategically important enough to balance the costs incurred from maintaining it? In at least two of the three scenarios Walt sketches out, it seems to me that the answer will be no.