The Case Against Jordan
Alan Dershowitz makes an interesting case against Jordan. The entire article is good, but I thought this was the point that would be most surprising for the majority of people:
Jordan killed more Palestinians in one month -- September 1970, known as Black September -- than Israel has killed during the three years of suicide bombings that began in the fall of 2000. The brutality of the Jordanian Army toward Palestinian dissidents and terrorists was far more egregious than anything Israel has ever done.
A subgroup of the Arafat-led Fatah movement took Black September as its name, but then went on to kill Israeli (not Jordanian) athletes at the 1972 Olympics.