The concept of Pan-Islamism as it has evolved is dual in nature, having both religious and political elements. King Faisal bin Abdul Aziz's dedication to Pan-Islamism had its genesis in the struggle for Arab unity and the Saudi-Egyptian rivalry for the leadership of the Arab world. Two phases of this inter-Arab conflict can be identified in tracing the historical evolution of King Faisal's Pan-Islamic movement: the 'Arab cold war', which resulted in the establishment of the World Muslim League in Mecca, and the 'Arab hot war', which produced Faisal's call for Pan-Islamic solidarity. To combat Gamal Abdel Nasser's radicalism and revolutionary socialism, Faisal, who was acting head of the Council of Ministers at the time, invoked Islam as a counter-ideology. With King Faisal's continuing support, the World Muslim League has become one of the most dynamic and authoritative of Muslim organisations, with branches and affiliates all over the world.