This chapter argues that after the Six Day War, Arab nationalism’s slide toward political marginality became irreversible. What stamped on it the sense of finality was the fact that it was Egypt under Gamal ‘Abd al-Nasir that lost. Indeed, Egypt’s devastating defeat was Arab nationalism’s mortal loss, for the fate of Arab nationalism during the struggles, triumphs, and reversals of the 1950s and 1960s was inexorably linked to Egypt and its charismatic president. Had it just been Syria or Jordan, or even both, who lost the war, it would not have been the unmitigated disaster for Arab nationalism that the June war turned out to be. But Arab nationalism could not survive the abject humiliation inflicted on its acknowledged prophet, who promised a fabled triumph in this al-Ma‘raka al-Masiriya, the battle of destiny.