The emergence of the regional power centers in the Third World is a manifestation of the unequal development of the international system. The domestic development of these centers is usually based on a close alliance between the state and the economic sector; and, varying from one state to another, on export of raw materials, on the substitution of imports and finally on the promotion of exports of goods and capital. In the last phase the external expansion of the regional centers is highly visible; they tend to create regional spheres of influence based on a multitude of economic, political, and military ties. Regional power centers today are cementing their regional spheres by military expansion, in turn greatly facilitated by the establishment of domestic capacity to produce conventional and even nuclear weapons. A strong military capability is an important characteristic of the regional centers. 'Mature' centers are relatively stable in political and economic terms, while the emerging enters tend to be more unstable, as the ase of Iran indicates. Other centers investigated in the article are Brazil, Venezuela, Nigeria, South Africa, and India.