Deterring the use of armed force and other forms of coercion is central to the maintenance of order in the Indo-Pacific. Yet from the Taiwan Strait and the South China Sea, to space, cyberspace, and the rules-based order itself, deterrence is becoming increasingly difficult to sustain in the face of major power competition, new grey zone challenges, emerging military technologies, and a rapidly shifting regional balance of power. The United States and Australia are determined to offset these trends by pursuing more integrated strategies for the Indo-Pacific. In recent months, the Trump administration has emphasised long-term strategic competition with China, placing renewed focus on technological dominance, geoeconomic statecraft, nuclear modernisation, and military readiness. In Australia, concerns over Chinese strategic policy, foreign interference, and the durability of American power and leadership have sharpened the focus on collective security and whole-of-government approaches to regional strategy. To advance a robust bilateral policy debate about the key role of deterrence in Indo-Pacific strategy, the United States Studies Centre and Pacific Forum hosted a Track 1.5 US-Australia Indo-Pacific Deterrence Dialogue in Canberra in December 2018. Both institutions thank the Australian Department of Defence and the Carnegie Corporation of New York for their generous support of this initiative. The following summary reflects the authors’ accounts of the dialogue proceedings and does not necessarily reflect their personal views. Nothing in the following pages represents the opinion of the Australian Department of Defence or any other officials or institutions that took part in the dialogue.

For decades, the rational actor model served as the preferred guide for U.S. deterrence policy. It has been a convenient and comforting guide because it requires little detailed knowledge of an opponent’s unique decision-making process and yet typically provides confident generalizations about how deterrence works. The model tends to postulate common decision-making parameters across the globe to reach generalizations about how deterrence will function and the types of forces that will be "stabilizing" or "destabilizing." Yet a broad spectrum of unique factors can influence an opponent’s perceptions and his calculations, and these are not easily captured by the rational actor model. The absence of uniformity means there can be very few deterrence generalizations generated by the use of the rational actor model that are applicable to the entire range of opponents. Understanding Deterrence considers how factors such as psychology, history, religion, ideology, geography, political structure, culture, proliferation and geopolitics can shape a leadership’s decision-making process, in ways that are specific and unique to each opponent. Understanding Deterrence demonstrates how using a multidisciplinary approach to deterrence analysis can better identify and assess factors that influence an opponent’s decision-making process. This identification and assessment process can facilitate the tailoring of deterrence strategies to specific purposes and result in a higher likelihood of success than strategies guided by the generalizations about opponent decision-making typically contained in the rational actor model. This book was published as a special issue of Comparative Strategy.

With many scholars and analysts questioning the relevance of deterrence as a valid strategic concept, this volume moves beyond Cold War nuclear deterrence to show the many ways in which deterrence is applicable to contemporary security. It examines the possibility of applying deterrence theory and practice to space, to cyberspace, and against non-state actors. It also examines the role of nuclear deterrence in the twenty-first century and reaches surprising conclusions.

Conventional Deterrence is a book about the origins of war. Why do nations faced with the prospect of large-scale conventional war opt for or against an offensive strategy? John J. Mearsheimer examines a number of crises that led to major conventional wars to explain why deterrence failed. He focuses first on Allied and German decision making in the years 1939–1940, analyzing why the Allies did not strike first against Germany after declaring war and, conversely, why the Germans did attack the West. Turning to the Middle East, he examines the differences in Israeli and Egyptian strategic doctrines prior to the start of the major conventional conflicts in that region. Mearsheimer then critically assays the relative strengths and weaknesses of NATO and the Warsaw Pact to determine the prospects for conventional deterrence in any future crisis. He is also concerned with examining such relatively technical issues as the impact of precision-guided munitions (PGM) on conventional deterrence and the debate over maneuver versus attrition warfare.Mearsheimer pays considerable attention to questions of military strategy and tactics. Challenging the claim that conventional detrrence is largely a function of the numerical balance of forces, he also takes issue with the school of thought that ascribes deterrence failures to the dominance of "offensive" weaponry. In addition to examining the military consideration underlying deterrence, he also analyzes the interaction between those military factors and the broader political considerations that move a nation to war.

Drawing on Chinese military writings, this report finds that China’s strategic-deterrence concepts are evolving in response to Beijing’s changing assessment of its external security environment and a growing emphasis on protecting its emerging interests in space and cyberspace. China also is rapidly closing what was once a substantial gap between the People’s Liberation Army’s strategic weapons capabilities and its strategic-deterrence concepts.

World events in recent years have led observers, particularly since late 2013, to conclude that the international security environment in recent years has undergone a shift from the post-Cold War era that began in the late 1980s and early 1990s, also sometimes known as the unipolar moment (with the United States as the unipolar power), to a new and different situation that features, among other things, renewed great power competition with China and Russia and challenges by these two countries and others to elements of the U.S.-led international order that has operated since World War II. The shift to renewed great power competition has become a major factor in the debate over future U.S. defense spending levels, and has led to new or renewed emphasis on the following in discussions of U.S. defense strategy, plans, and programs: * grand strategy and geopolitics as part of the context for discussing U.S. defense budgets, plans, and programs; * nuclear weapons and nuclear deterrence;* new U.S. military service operational concepts;* U.S. and NATO military capabilities in Europe;* capabilities for conducting so-called high-end conventional warfare (i.e., largescale, high-intensity, technologically sophisticated warfare) against countries such as China and Russia; * maintaining U.S. technological superiority in conventional weapons;* speed of weapon system development and deployment as a measure of merit in defense acquisition policy;* mobilization capabilities for an extended-length large-scale conflict against an adversary such as China or Russia;* minimizing reliance in U.S. military systems on components and materials from Russia and China; and* capabilities for countering so-called hybrid warfare and gray-zone tactics employed by countries such as Russia and China.

To explore what extended competition between the United States and China might entail out to 2050, the authors of this report identified and characterized China’s grand strategy, analyzed its component national strategies (diplomacy, economics, science and technology, and military affairs), and assessed how successful China might be at implementing these over the next three decades.