The title is literal. John Bartlow Martin was our first post- Trujillo Ambassador to the Dominican Republic. After the ouster of Juan Bosch, he returned to Washington and was working on the question of relations with the new military regime when President Kennedy was assassinated. He then wrote most of this tremendous book. In April, 1965, President Johnson sent him back to Santo Domingo as a special envoy during the civil war. Aside from a relatively brief section on Dominican history, then, this nearly 800-page volume is devoted to a four-year span. Mr. Martin's elected task here is to demonstrate how U. S. foreign policy works (or doesn't) in a small, troubled country, and specifically how circumscribed our powers can be. In the process he attempts to justify both the U. S. intervention in the civil war and the U. S. failure to intervene on Bosch's behalf during the 1963 coup. He also maintains that ""we shall have to come to terms with emerging revolutions,"" and even recognize Communist governments in some of them. In a book so large, so full of detail, written in the middle of swift events, inconsistencies are no doubt unavoidable, but Martin seems to have set a new record. He has, in his care to offend no one in a position to reply, managed to say remarkably little at enormous length.