This chapter focuses on the brief moment when pan-Arab federalism, often associated with Gamal Abd al-Nasser and Egypt, became a general political desire, exemplified by several short-lived unions. The short-lived unions are the United Arab Republic of Egypt and Syria (UAR) and the United Arab States (UAS); a confederation of Egypt, Syria and North Yemen from 1958 to 1961, as well as the failed Federation of Arab Republics promoted by the Libyan leader Muammar al-Gaddafi. The rise of Islamist extremists in relation to attendant issues such as weak/failed statehood politicized social and military institutions, political vacuums that allow groups to leverage violence as a substitute for formal processes and institutions of political participation. The complex dynamics that animated pan-Arabism indicate the necessity of framing the history of federalism in the region in terms of transnational sovereign power issues.