In the Arab world, communities of believers (Ummah), the Arab nation, states, tribal communities, and minority groups are reference points that cut horizontally across the region and compete with the verticality of States. While the notion of national security was developed in the West based on a specific process largely rooted in the primacy of States over other references, in the Arab and Muslim world, the dynamics currently at play (transitions, civil war, crises in post-colonial States) reveal contradictions between the dynamics of State building and community or tribal dynamics. These contradictions can be seen not only in current inter-Arab relations, which harken back to an old model of dealings between Arab States, but also in relations between Arab States and the world powers of the day.