When in 1950 the United Nations called upon its members to provide aid to South Korea, more than forty nations responded. Some of these sent troops which fought under the United Nations Command, some sent commodities and medical supplies. Some nations offered moral and political support but for a variety of reasons were not able to send aid. This book looks at the nations involved, what was behind their willingness to provide troops or aid, or what prevented them from doing so. The military contribution of the nations involved is discussed. The combination of troops, and their individual needs, made the logistics of this enterprise difficult, but in the end troops from 17 nations fought together to defend the freedom of South Korea.