UNITED NATIONS, Sept. 25 -- Mahmoud Abbas has not set foot inside this building in two years. On Wednesday, the screen carrying his recorded voice drew applause from a chamber that had gathered to hear him. A day later, when Benjamin Netanyahu walked to that same podium in person, most of that chamber was already gone.

Seventy-seven national delegations left the General Assembly hall before Netanyahu began speaking Thursday, according to Fox News, which reported that representatives from Arab, Muslim and African states led the exodus as he approached the podium. By the time he reached it, the hall held little more than the American delegation and a scattering of others. Netanyahu spoke to the empty seats as much as to the ones that remai...