Measuring the Euro~?ean Conventional Balance Coping with Complexity in Threat Assessment scarce resources wisely in the coming years, if it I If NATO is to invest its is to choose intelligently from the menu of possible conventional improvements,’ it must begin with a careful assessment of the current NATO-Warsaw Pact military balance in Central Europe. Such assessments can only provide useful program guidance This article is a substantially revised version of “Competing Views of the Center Region Conventional Balance,” in Keith A. Dunn and William 0. Staudenmaier, eds., Alternative Military Strategies for the Future (Boulder, Colo.: Westview Press, forthcoming). The author wishes to thank all of the friends and colleagues who provided comments on various drafts of this essay. He also wishes to thank the Council on Foreign Relations and the Rockefeller Foundation for their financial support. The author alone is responsible for the content of this essay. Barry Posen is an Assistant Professor in the Department of Politics and the Woodrow Wilson School at Princeton University and the author of The Sources of Military Doctrine: France, Britain, and Germany between the World Wars (Ithuca:Cornell University Press, 1984). 1. The wide range of possible improvements may be loosely grouped into three categories: those of the ”military reformers,” who advocate a host of tactical, organizational, and hardware changes that would improve conventional capabilities without major spending increases; those of the NATO (and Pentagon) bureaucracy, which has made a battery of proposals (such as the Long Term Defense Plan) simply to buy a lot more of what we have been buying; and those of a group of technology-minded individuals who advocate investments in “new” technologies (usually called “emerging technologies” or ”E.T.”). For a criticaldiscussion of the possible tactical implications of the military reformers’ prescriptions for ground warfare, seeJohnJ. Mearsheimer, “Maneuver, Mobile Defense, and the NATO Central Front,” International Security, Vol. 6, No. 3 (Winter 1981/82), pp. 109-122. For the best example of how the reformers’ ideas have crept into officialU.S.Army doctrine, see U.S. Army, FM 100-5, Operations (August 20,1982).The reformers are also keenly concerned about weapons design. Their prinapal criticism of current U.S. weapons design philosophy is that it strives fortechnologicalparameters that are too far removed from the actual circumstances of both peacetime and wartime military practice. For a useful reform perspective on the technology of ground warfare, see Steven Canby, The Alliance and Europe: Part IV, Military Doctrine and Technology, Adelphi Paper No. 109 (London: International Institute for Strategic Studies, 1974/75), pp. 34-41. On aerial technology, see Jack N. Menitt and Pierre M. Sprey, ”Negative Marginal Returns in Weapons Acquisition,“ in Richard G.Head and ErvinJ. Rokke, eds., American Defense Policy, 3rd ed. (Baltimore:Johns Hopkins University Press, 1973), pp. 486-495. On the Long Term Defense Plan, see Harold Brown, Annual Report of the Deparhnent of Defense, Fiscal Year 1981 (Washington, D.C.: U.S. Government Printing Office, 1980), pp. 47-49, 215. For arguments in favor of ”emerging technologies,” see Strengthening Conventional Deterrence in Europe, Report of the European Security Study (NewYork St. Martin’s Press, 1983). Znternational Security, Winter 1984/85 (Vol. 9, No. 3) 0162-2889/84/030047-42$02.50/1 0 Barry R. Posen. 47 lnternational Secwify 1 48 if they focus on the most dangerous threats facedby the Alliance, and capture as fully as possible the efforts NATO has already made to deal with those threats. Most assessments, unfortunately, are too simplistic, relying heavily on simple ”bean counts” and failing to take adequate account of the many other variables involved. This analysis will explain what some of these other variables are and how they may be combined into a model that will provide a more realistic balance assessment and a basis for evaluating possible improvements . The Problem The distinctive characteristic of military competition in Central Europe is the large concentration of mechanized ground forces on both sides, supported by substantial numbers of attack helicopters and fighter aircraft. Most assessments give the Warsaw Pact credit for quantitative superiority in these assets. These are the same kinds of forces that are associated with the major blitzkriegoperations of the last half...