This is subtitled ""American Civilians in Rural Vietnam. "" Credit is also given on the title page to W. Robert Warne, Earle J. Young, and William Nighswonger, each of whom is responsible for a chapter dealing with one of the three major geographic divisions of the country. These men are Provincial Representatives, part of one small but important section of the U.S. Operations Mission in Vietnam: the Office of Provincial Operations (originally the Office of Rural Affairs). Their job is to bring into being ""a Vietnamese 'New Deal' with a definite program and psychological appeal,"" to compete with the social and economic promises of the Communists. They live and work in the provinces, ""spurring on the local officials,"" trying to understand the peasants and to remedy their many grievances. There are slightly more than 100 PR's in South Vietnam, ""any of whom,"" says Mr. Tanham, ""could write a book about his experiences."" Many have their families with them and they usually go unarmed, despite the fact that every single one ""has been shot at or ambushed, several have been wounded, and one has given his life."" There is no doubting their dedication or the sincerity of their efforts, to go ""down to the grass roots, to help the Vietnamese build a nation, a viable economy, and a healthy society."" Certainly this book deserves close attention, particularly now, as our commitments continue to mount. The trouble is, you see, Asian grass has very deep roots.