The Middle East has been a hotbed of ethnic conflict for centuries, but the level of violence there intensified in the twentieth century largely as a consequence of the struggle between Jews and Arabs for land and statehood in “holy” Palestine. Protracted efforts to end that struggle have spawned, inter alia, the Camp David Accords between Egypt and Israel, and the Oslo Agreement between the Palestine Liberation Organization (PLO) and Israel. But in these and other cases, religious extremists have opposed conciliatory efforts so fiercely as to resort not only to terrorism, but to assassination of the peacemakers themselves. What ties together assassinations such as those of Egyptian president Anwar el Sadat and Israeli prime minister Yitzhak Rabin is a special type of religiously inspired political violence that might be termed messianism. The messianic model was first proposed by David C. Rapoport in his study of “holy terror,” and further developed in my own application of the model to the Sadat and Rabin cases.1 In this essay I shall test the model further by focusing on the assassination of yet another peacemaker, King Abdullah ibn Hussein al Hashem of Jordan, on July 20, 1951. He was killed by Mustafa Ashu (a Palestinian disciple of the exiled mufti of Jerusalem, Hajj Muhammad Amin al Husseini), who thought the king was carrying out secret and separate peace negotiations with Israel. Should this third case study confirm the findings of the first two, one may conclude with confidence that the phenomenon of messianism is a major stumbling block on the road to peace in ethnic conflicts staked by spiritual passions.