Picture a Palestinian leader in the twilight of his reign. Besieged on all sides and challenged by younger upstarts, he lashes out against Israel, his Arab brethren, and the United States. Other Palestinian officials jockey to replace him, convinced he’s past his prime. This is how it ended for Yasser Arafat, whose insistence on waging the second intifada left him isolated in the final years of his rule. It may well be how it ends for Mahmoud Abbas.