Fleischman makes a compelling argument that an Israeli-Palestinian peace agreement requires the cooperation of Arab states. He also argues for Jordanian-West Bank and Egypt- Gaza federations.
Hatred of Israel, Fleischman contends, is so ingrained among Palestinians that no bilateral agreement is possible. On the other side, he criticizes Israeli settlement policy on the West Bank, presenting it, too, as another obstacle to peace, but less so than Palestinian hostility.
Changes in Arabic-speaking countries, especially the "Arab Spring" uprisings have meant a turn inwards and less concern with confronting Israel, as shown by the Abraham accords, which the author hopes can be a precursor to an Israeli-Palestinian peace agreement facilitated by the Arab states. However, he never actually explains how the Arab states might accomplish this but assumes it as a given.
While Middle East Riddle contains much of value, depending on Jordan and Egypt to resume their old roles is problematic. Would Jordan's King Abdullah II want to federate with the West Bank? A highly problematic history presumably accounts for his showing no inclination whatsoever to return to the 1948-67 era. Likewise, Egypt's Abdel Fatah Sisi came to power in 2013 via a military coup that ousted the Muslim Brotherhood regime; but a federation with Gaza would legitimize Hamas. In addition, Hamas has smuggled arms to the ISIS subsidiary fighting the Egyptian government in the Sinai Peninsula.
In sum, while Fleischman makes good points, his suggestion to solve the Israeli-Palestinian conflict through federations between Jordan and the West Bank and Egypt and Gaza appears unrealistic.