A survey of the complexities of the problems of national minorities, especially those of east-central Europe, as they affect post-war planning. With the background of the solutions offered by Western Europe, Switzerland, South Africa and the Soviet, and a criticism of the League system following the last war, a composite is worked out for a multinational state and national federalism that will insure order, unity and national harmony. The idea of force, of transferring of peoples is vetoed; the protection of the minorities is promised and the international guarantee of the United Nations is understood. A specific, rather than global, approach to the mechanisms necessary for overcoming linguistic and cultural blocks, for the regimes governing geographical and economic units. For technicians of international policy chiefly.