Asia's strategic politics are likely to be the growth sector in International Relations in the next 20 years as academics and practitioners attempt to keep analysis and commentary apace with regional developments in security and diplomacy. These two books provide important contributions to the study of this field, but with quite different perspectives and methodologies. Thomas J. Christensen's book is the more ambitious since it has important hypotheses to test on the nature of successful and unsuccessful alliance management in East Asia. In contrast, the book by Andrew J. Nathan and Andrew Scobell largely eschews theory and aims for a rich empirical account of China's contemporary security policy and capacity.

Christensen's concern is with coercive diplomacy defined as “the use of clear and credible threats and assurances in combination to dissuade target countries from undesirable behaviour” (p. 2). It may seem evident that, the more unified and integrated an alliance is, the more challenging coercive diplomacy becomes, but Christensen argues the opposite: Intra-alliance divisions and rivalries greatly complicate the organisation and communication of threats and assurances from, and towards, such an alliance. In order to test this first hypothesis Christensen conducts detailed historical analysis of how the alliance systems interacted in East Asia across a 25 year period, from alliance formation in the late 1940s to escalation in Southeast Asia and the U.S.-China rapprochement of the early 1970s. His specific cases are: the lack of coherent signalling from both alliances during the period of alliance formation and how this contributed to misjudgements especially in the onset and escalation of the Korean war, 1949–51 (chapters 2 and 3); an interim period, 1951–56, when the communist camp was at its most ideologically and organisationally coherent and effective diplomacy was achieved in Northeast Asia and Indo-China (chapter 4); the onset and escalation of the Sino-Soviet dispute, 1957–72, and the opportunity this generated in the communist camp for subordinate members of the alliance to advance their objectives at the expense of stability in the regional system overall (chapters 5 and 6); and the decline of coercive diplomacy in the US-China relationship in the final decades of the Cold War, 1972–91, but the return of certain aspects of coercion in the post-Cold War period especially due to changes in the US-Japan relationship and on Taiwan (chapter 7). By careful and detailed examination of primary and secondary sources on the diplomatic and strategic calculations of key actors—particularly Chinese and American leaderships—Christensen skilfully justifies his hypothesis that alliance cohesion allows effective communication of threats and assurances, resulting in a virtuous environment of mutual comprehension and predictability; whereas intra-alliance division leads to loss of communicative efficiency and increases the potential for misunderstanding, unpredictability, and miscalculations on the use of force.

If Christensen justifies his hypothesis in terms of outcomes, this still leaves open whether his explanation for the outcomes is valid. This depends on the nature of the political relationships that produce different structures and dynamics in alliance systems. Christensen's second hypothesis is that it was the particular politics and structures of inter-communist alliances that rendered coercive diplomacy in Asia so problematic. He argues that the two predominant characteristics of these alliances were revisionist ideology and divided hierarchy. First, communist alliances are formed around revisionist ideologies and this encourages intra-alliance competition due to “potentially differential levels of devotion to specific revisionist conflicts” (p. 262). Secondly, he notes problems of hierarchical binding: Divisions in the leadership of the communist movement—as in the Sino-Soviet rivalry—create conditions in which “alliance members will make decisions to support aggression for reasons that go beyond the corporate interests of the alliance as a whole” (p. 263). However, it is possible to advance other explanations for these dynamics. One factor that was evident in the Cold War and remains so today is the absence of a tradition of alliance building in Asia. When the United States and USSR organised their alliances in Europe in the early Cold War period, Europeans had been using alliances to conduct advanced balance of power politics for at least 300 years—Cold War alliances were a continuation of normal politics. There was no such tradition of alliance organisation in Asia and the U.S. alliance today remains only one mechanism for managing power/threat dynamics across the region. Differences in traditions of alliance building need to be considered as a factor shaping the organisation of coercive diplomacy in the Asian Cold War and after. If one were to point to the specifics of communist systems, moreover, it might not be differential devotion to revisionist causes that most accounts for their tendency toward intra-alliance strife. All Leninist systems are substantially de-constitutionalised; power is arbitrated by a number of informal mechanisms, not least factional struggle. At particular points in Cold War history, leadership successions and policy decisions within communist states, including both the USSR and China, were arbitrated by just such an intense personal and factional struggle. It was almost inevitable that such inner-party struggle would be replicated in inter-party competition across the communist movement, especially when ruling factions were in the hands of such volatile leaders as Khrushchev and Mao. Ideology was an important aspect of such struggles, both cognitively and instrumentally, but it never was a particularly good guide to what Soviet, Chinese, or other communist leaderships would do next. Therefore analysts of communist systems will readily agree with Christensen that it was something in the nature of communist politics and systems that made them unstable alliance partners and difficult targets for coercive diplomacy, but in likelihood variable commitment to revisionist goals was only one factor among others.

Nevertheless, Thomas J. Christensen's important book does great service to the study of strategic politics in two ways. It encourages us to think of coercive diplomacy—the effective communication of threats and assurances—as being the most likely route to regional stability in Asia until such time as effective security institutions are developed. Secondly, the book is very persuasive in its methodology; the careful reading of primary and secondary sources to develop historical case studies that can be used to test hypotheses about structures and dynamics within and between alliances over time is very helpful for analysts on a wider range of contemporary strategic problems, a point Christensen makes himself in his concluding chapter.

Nathan and Scobell's China's Search for Security, a largely empirical account of contemporary issues in Chinese security, could best be described as a compendium of security analysis on China. The book is divided into five parts. Part 1 has two chapters that examine the drivers and decision-making of Chinese security policy. Part 2 has five chapters devoted to the geopolitical dimensions of China's security—great power relationships and regional environments. Part 3 returns to the domestic sphere and discusses problems of territoriality with one chapter on Tibet, Xinjiang, Hong Kong, and Taiwan as territorial issues, and one chapter on the consequences of political change in Taiwan. Part 4 has three chapters on what are called the instruments of Chinese power: China's global economic role, military modernisation, and China's soft power and human rights profile. Part 5 has a concluding chapter that discusses whether China's new power will aim at sustaining equilibrium in the global system or will seek to overturn the current system. The authors' primary claim is that, even given the considerable expansion in the power instruments and geopolitical parameters of Chinese interests in the last 20 years, the main objective of Chinese security policy remains defense: “to blunt destabilising influences from abroad, to avoid territorial losses, to moderate surrounding states' suspicions, and to create international conditions that will sustain economic growth” (p. xiii). This further leads them to conclude that China has more to lose than gain from challenging the current international order and its institutions, and that the long-term goal of Chinese policy is a new equilibrium within that order that accords China the status that its self-image and interests require (p. 356). Nathan and Scobell do an admirable job of organizing and presenting their analysis across a comprehensive range of issues, but there remain some limitations in their approach. First, whether China's expanding capacities and interests are interpreted as defensive or offensive, as seeking revision or equilibrium, is substantially a problem of perception not just of fact. To put this in Christensen's terms, can China get the balance right between persuasive and coercive diplomacy, between encouraging compliance with its interests when appropriate and enforcing compliance when necessary? China's resort to coercive diplomacy around its self-defined core interests does seem defensive from the Chinese perspective, but is often not perceived as such by those in receipt of its sanctions. This suggests the largest and least predictable variable in China's security politics is China's identity, or more precisely the gap between China's self-perception of legitimate security interests and mechanisms, and others' perception of these. Nathan and Scobell do discuss the role of history, culture, ideology and nationalism as drivers of China's security identity, but these are only accorded 18 pages out of 400. Some readers may wish that the relationship between identity and behaviour was explored more fully. Secondly, as a compendium of security issues, there is some variance in the value of specific chapters. To give examples from the instruments of power section, the chapter on military modernisation is an excellent summary that covers doctrine, structure, technical up-grading and core missions. The preceding chapter considers China's global systems integration, focusing primarily on economic internationalisation but also pointing briefly to environmental vulnerability, information security, and proliferation issues. This chapter is less effective not because the right issues are not identified but because large and complex questions such as these cannot be adequately reviewed in a chapter. Having taken on the task of offering a comprehensive account of China's security behaviour, the authors' unavoidably find themselves having to compress certain key issues with some loss of value in consequence. These limitations aside, the contribution of Nathan and Scobell is likely to be widely read and used in debates about China's changing security roles.

Perhaps the most interesting thing about reviewing these two books together is that they reveal how large and diverse the field of Asian strategic politics has become. From quite different methodological approaches and problem areas they represent useful complementary perspectives on how a predictable peace for Asia might be secured.