Understanding the relationship between Islamism and Arab nationalism has always been problematic. The separation between Islamists and Arab nationalists, and political conflict between them is a relatively late development in modern Arab history. From the early 1950s, a series of military coups brought young Arab nationalist military officers to power in many Arab countries, including Egypt, Syria, Iraq, Yemen and Algeria. Arab nationalism, expressed in exclusive, radical and even socialist discourse, became the official ideology of these Arab states. The military background of the ruling forces, their fragile base of legitimacy, and the sweeping programs of modernization and centralization they pursued, turned most of their republican, nationalist countries into authoritarian states. One of the major results of this development was the eruption of a series of confrontations between Arab nationalist regimes and Islamic political forces, in which questions of power, identity and legitimacy were intertwined.