The Boston Study Group--comprising concerned academics with solid credentials--presents a forceful argument for a reduction in the size of both the armed forces and the military budget without a loss of defense capability. Starting with the present policy--defend the U.S.; support Western Europe, Japan, and Israel; deter war--the book contends that ""A large part of the military establishment is not needed for these purposes."" It is, moreover, ""perpetuating force and spending levels . . . for reasons which no longer hold."" Not a new theme, but calmly presented this time via a logical analysis of defense needs--based on comparison of world-wide military forces and national policies with our own--and followed up by detailed recommendations for savings in cost and size. Present policies, notoriously, are promoted by a ""defense-producers lobby"" of several million military and allied workers, while there is no effective ""defense-consumers lobby."" The Boston Study Group points out in this connection that only a small percentage of defense money is spent on actual ""national defense""; most is spent on ""deterrence"" and on conventional forces and weapons structured to operate abroad. The recommended reductions, furthermore, are to take place over five to ten years. Examples: eliminate nearly all land-based missiles (present nuclear over-kill status is well-known); do away with the Trident submarine program (additional excess capacity), leaving the Poseidon group; eliminate manned strategic bombers; reduce the carriers to three operating vessels; cut overseas arms sales by 50%; take most basic research away from the military. Overall, the authors maintain, the budget can be reduced from the present 120 billion to 73 billion by 1980, and kept there. Startling? Certainly to the military and to civilian hawks, but the logic of the arguments will be hard to refute.