The Marine Corps is engaged in what appears to be a new and different kind of conflict in Vietnam. Because there is reason to believe this may be the pattern of Marine involvement for some time to come, an effort was made to define, as a system, what is taking place in Vietnam. It appeared that such a definition, if successful, might provide a prototype of future Marine activities and therefore be useful as a basis for design of training subsystems. Because the Mission is to support, and rally support for, the indigenous government and its social, economic, and political programs, the system is given the name counterinsurgency support. To test the extent to which the attitudes of Marines were supportive toward the Vietnamese, an Opinion Survey was given to 2,744 Marines in various stages of training and in Vietnam. Marine attitudes Improved with time in the Corps and particularly in Vietnam, but negative attitudes still characterized a significant proportion of Marines in Vietnam. On the basis of an analysis of the above studies three primary recommendations have been made for Marine Corps consideration and action.