This treatise by two Australian on the pros and cons of a United Nations Military force is the fourth in the series of the Princeton Studies in World Politics. Three main points are raised in an objective discussion of the United Nation's Congo and Middle East operations. First, the importance of maintaining the scope and authority of the Secretary General's office (an expansion of this argument would have been helpful): second, the need for some form of legal authority within the ""host"" country for ""occupying non-political and non-interventionist ultra-national forces"", and third, the weaknesses inherent in an ad hoc organizational force and their possible correction. The authors conclude, in this formal, detailed report, that although the Congo operation dented the UN's moral authority due to the political results of intervention, the crisis was produced by human factors -- breakdown in communications between people on the spot and in New York -- rather than by an inrinsic fault in the UN Charter. For the student of world affairs, not the general reader.