International peace and security depend on certain taboos that are easily recognized when they are broken. It can be more important for an intervention to take place because nuclear or chemical or biological weapons are used as opposed to just measuring how many people are killed.
The disappearance of Israel as a Zionist project, through war, cultural exhaustion or demographic momentum, is... plausible... Many Israelis see the demise of the country as not just possible, but probable.
For the U.S., as the largest player in the global environment, unintended consequences are magnified.
The leadership of the Palestinian Authority is not held in high regard by most of the population of the West Bank. They're seen as living relatively high off the hog and certainly not accomplishing anything vis-a-vis the Israelis.
