The end of the Cold War left the United States in the fortunate position of facing no imminent threat of global war. But it also left the United States in a strategic vacuum, with no organizing principle for its national security. This book proposes a security strategy for the 21st century based on preventing new major threats to U.S. security from emerging.

Informed by the authors' service in the Pentagon during President Clinton's first term, this book identifies six major dangers to U.S. security that have the potential to grow into threats to American interests and values as ominous as the Cold War's nuclear standoff. In chapters that cover chilling dangers ranging from Russia's implosion to the rising power of China, and from proliferation of biological weapons to cyber terrorism, the authors first recount from first hand experience the Pentagon's efforts to define and prevent dangers to U.S. security since the end of the Cold War, and then advance preventive defense strategies for the future. It argues that implementing a Preventive Defense strategy will require a revolution in the way the Pentagon does business -- a revolution that is only beginning.

Can the current global moratorium on nuclear weapon testing survive the May 1998 tests by India and Pakistan and the refusal of US Senate leaders to permit consideration of the Comprehensive Test Ban treaty (CTBT) by the Senate? If nuclear testing resumes by India or Pakistan - or by Britain, China, France, Russia, or the United States - will it be condemned by most of the world as if an international norm against testing was already in effect? What will be the likely consequences for nonproliferation if tests resume? This article seeks to show that there are norms operating against nuclear testing even though the CTBT has not been ratified, and that renewal of testing would have widespread consequences.

This report is the result of a workshop held in April 1998, when fifty policy experts, government officials and scholars met in Washington, DC. to discuss an issue of great import: the future of the relationship between Ukraine and NATO, This event, the Workshop on Ukraine-NATO Relations, was sponsored by the Harvard University Project on Ukrainian Security and the Stanford-Harvard Preventive Defense Project. The express goal of the workshop was to bring together representatives of Ukraine, NATO, and the United States so that they could collaborate on developing concrete recommendations for short and long-term next steps to broaden and deepen Ukraine-NATO relations.

The conveners of this workshop believed that the relationship developing [at that time] between Ukraine and NATO had the capacity to evolve into an important force for stability and security in Europe and the world, and to serve as a model for other countries in the region. While the NATO-Ukraine Charter and Ukraine's participation in the Partnership for Peace and the NATO peacekeeping mission in Bosnia provided a strong foundation, the longer-term direction of this very important relationship continued to be largely undefined. Further, they strongly believed that the Charter on a Distinctive Partnership signed by Ukraine and NATO in the summer of 1997 was only the first step towards institutionalizing the growing Ukraine-NATO relationship. Ensuring that the Charter was meaningful depended on concrete implementation of the cooperation anticipated in that document. Thus they decided that a concerted effort needed to be made to develop a gameplan for the future.

Russia's current strategic nuclear force will become obsolete shortly after the turn of the century. Strategic modernization is therefore essential if Russia is to remain a nuclear power on a par with the US. But modernization will be extremely difficult because of the country's economic and political turmoil. Russia can probably maintain slightly more than 4,000 strategic nuclear warheads under the Strategic Arms Reduction Talks (START) I Treaty - roughly half of what the United States could, in theory, deploy. Under START II, Russia's strategic force will likely contain between 1,800 and 2,500 warheads, compared to 3,500 for the US. Hence, the easiest - perhaps the only - way for Russia to recover rough parity with the United States would be through a START III Treaty that limits both sides to 2,000-2,500 warheads.

This paper examines how well future U.S. national and theater missile defense systems will have to perform to meet reasonable defense objectives as a function of the level of the threat. Deploying a thin U.S. national missile defense today is premature because the threat is not readily apparent, the United States can deter most threats, and the United States has some conventional counterforce options against a developing state's nascent ICBM arsenal.

However, if, or when, intercontinental ballistic missile threats appear, a defense with 100 interceptors deployed at one or two sites around the continental United States should be able to to intercept between 10 and 20 apparent warheads, assuming NMD systems can detect and track warheads with a probabilty above 0.99 and that NMD interceptors have a single-shot probability of kill (SSPK) against warheads between 0.35-0.65. Theater-range ballistic missiles present a greater near-term threat. The current THAAD program may provide an effective upper-tier defense, but only if it can achieve detection and tracking probabilities in the range 0.96-0.98 and interceptor SSPKs in the range 0.4-0.65 for threats with between 100-200 apparent warheads. Larger threats will require even higher technical performance.

Similarly, the current NTW program will require the same detection and tracking probability, but with interceptor SSPKs in the range of 0.55-0.80 to deal with the size of the threat.

Moreover, for these defenses to be truly useful, they must be accompanied by an equally effective lower tier, e.g., using PAC-3 terminal defenses. The main challenge for upper- and lower-tier defenses is responsive threats that use countermeasures such as decoys and chemical or biological submunitions. Airborne boost-phase theater missile defenses are relatively robust with respect to these countermeasures and they pose relatively little threat to the nuclear forces of the five major nuclear powers. Hence, more emphasis should be placed on such systems in current U.S. missile defense plans.

This report is a product of the Catastrophic Terrorism Study Group, a nine-month long collaboration of faculty from Harvard University, the Massachusetts Institute of Technology, Stanford University, and the University of Virginia. The Group involves experts on national security, terrorism, intelligence, law enforcement, constitutional law, technologies of catastrophic terrorism and defenses against them, and government organization and management.

The Group is co-chaired by Ashton B. Carter and John M. Deutch, and the project director is Philip D. Zelikow. Organized by the Stanford-Harvard Preventive Defense Project, the work of the Study Group is part of the Kennedy School of Government's "Visions of Governance for the Twenty-First Century" project, directed by Dean Joseph S. Nye, Jr. and Elaine Kamarck.

While the danger of catastrophic terrorism is new and grave, there is much that the United States can do to prevent it and to mitigate its consequences if it occurs. The objective of the Catastrophic Terrorism Study Group is to suggest program and policy changes that can be taken by the U.S. government in the near term, including the reallocation of agency responsibilities, to prepare the nation better for the emerging threat of catastrophic terrorism.

As Russia undergoes transition from a command to a market economy, almost all aspects of the economic landscape are changing. One of the more promising changes is the emergence of entrepreneurship. Entrepreneurship depends heavily in turn on the availability of financing and advice for new businesses. For the past several decades in the United States this help has come largely from venture capitalists, so it is logical to consider the role that venture capital can play in Russia. Some understanding of this role can be gleaned from reviewing the development of venture capital in the United States. This paper reviews this development and suggests ways of building and utilizing venture capital firms in Russia, recognizing that there are many differences between the circumstances in Russia and those surrounding the development of venture capital in the United States.

The majority of Russia's current strategic nuclear force will become obsolete shortly after the turn of the century. Hence, Russian strategic force modernization is essential if Russia is to remain a nuclear power on a par with the United States. Numerous uncertainties, especially financial uncertainties, prevent accurate estimates of Russia's future strategic force structure. Nevertheless, under the START I Treaty, Russia can probably maintain a force with slightly more than 4,000 strategic nuclear warheads over the next two decades-about half the number of the United States. Under START II, Russia is likely to maintain a strategic force of between 1,800 and 2,500 warheads, compared to 3,500 warheads for the United States. Therefore, Russia's main interest in ratifying the START II Treaty would be to pursue a START III Treaty that limits both sides to between 2,000 and 2,500 strategic nuclear warheads. This is the least expensive way to retain rough parity with the United States. Several reasons have been educed for why Russia should not ratify the START II Treaty, namely, because the Treaty allows a U.S. advantage in reconstitution capability and prompt hard-target-kill capability. However, these advantages are neither so great nor so consequential that Russia should reject the START II Treaty for these reasons alone. If Russia ratifies the START II Treaty, and presumably a follow-on START III Treaty, Russia's future strategic nuclear force will appear a lot different than its Soviet predecessor due to the reduced emphasis on land-based ICBMs. Nevertheless, the Russian force should remain a highly survivable, stable force-assuming Russian leaders allocate sufficient resources to ensure that their ballistic missile submarines, mobile ICBMs, and bombers can survive all plausible counterforce threats.

If high-performance computing (HPC) export control policy is to be effective, three basic premises must hold:

This study applies and extends the methodology established in Building on the Basics [1]. Its objective has been to study trends in HPC technologies and their application to problems of national security importance to answer two principal questions:

· Do the basic premises continue to be satisfied as the 20th century draws to a close?

· In what range of performance levels might an export-licensing threshold be set so that the basic premises are satisfied?

The study concludes that export controls on HPC hardware are still viable, although much weaker than in the past. In particular, while applications of national security interest abound, it is increasingly difficult to identify applications that strongly satisfy all three basic premises, i.e. are of extreme national security importance and would likely be effectively pursued by countries of national security concern and would be severely retarded without levels of computing performance that could be effectively controlled.

This report on non-binding, non-treaty approaches to arms control draws upon research and discussion at the Center for International Security and Arms Control during 1990 and 1991, after the Cold War had ended but before the disintegration of the Soviet Union. It was apparent at the time that the traditional approach to arms control--through detailed treaties resulting from long negotiations--might not be adequate to deal with the new situation in which arms reductions could be made quickly but coordination would still be needed in order to preserve stability. We examined the possibility of using reciprocal unilateral measures (RUMs) in place of treaties as a mechanism for achieving arms control.

A striking example of the approach we were recommending was when Presidents Bush and Gorbachev announced major withdrawals of non-strategic nuclear weapons in September and October 1991 (We describe the Bush-Gorbachev RUMs in this paper.) The strategic picture changed dramatically soon after those measures were announced. The Soviet Union was replaced by the Russian Federation and 14 other newly independent states. For several years, the treaty method worked well in U.S.-Russian arms control, alongside other forms of cooperation such as the Nunn-Lugar program. We put aside our work on RUMs.

Although we are far from a resumption of the Cold War, U.S.-Russian relations are no longer as cooperative as they were in the early 1990s. Besides, the treaty method has slowed almost to a standstill. We have therefore returned to the draft final report of 1991 and drawn from it the history we thought is relevant to the current problem of reducing the strategic nuclear threat Russia and the United States pose to each other--and to the rest of the world.