Joshua Shifrinson, in his review of Restraining Great Powers: Soft Balancing from Empires to the Global Era, offers a succinct summary of the book’s key arguments and their merits and drawbacks. He presents a number of contributions the book makes and raises some questions surrounding my arguments. One issue is the need for more clarity regarding the causal mechanisms. To be clear, the causal mechanism of the argument is built largely around reputational considerations. First, a potential aggressor may be restrained by knowing that its reputation will suffer and that it will not get the needed support from others, including traditional allies sometimes. Second, the notion of collective legitimation is introduced, suggesting that the support or non-opposition of international institutions like the UN is needed for effective intervention or its later success. Third, soft balancing and associated reputational considerations can affect the aggressor’s domestic politics. The US electorate’s voting Barack Obama into office in 2008, thereby repudiating the Bush administration’s Iraqi intervention, is a case in point. During his campaign, Obama had successfully used the argument that the United States had lost its global legitimacy and the support of its allies and that he wanted to restore both. The electorate agreed. Finally, states often resort to soft balancing as a signaling mechanism to show displeasure, especially if they have limited military capabilities or intentions to engage in a deeply confrontational response.

Although I agree that soft balancing can be a complement to the balance of power theory, I have also shown that balancing against threats is more important than against aggregate power. I argue that, as the threat level increases, soft balancing can develop into limited and full-fledged hard balancing, and this progression is not captured in the traditional balance of power theory. In fact, traditional balance of power theory is about power and not threats, and it was Steven Walt (The Origins of Alliances, 1987) who showed that states tend to balance more against threats than against power. Hardcore realists tend to reject all the secondary mechanisms I discuss in the book as insignificant. For instance, John Mearsheimer and Susan Strange both have rejected institutions as epiphenomena of power and therefore of limited significance to world politics. There is an exclusive focus on the hard mechanisms of alliances and arms buildups in realist theory. The emerging literature that Shifrinson cites is in the right direction but has yet to become mainstream. Showing that different levels of threat elicit different balancing responses brings the theory closer to reality and places it beyond the domain of stringent conditions for balancing that only recur occasionally, despite claims by structural realists.

The case studies in the book offer discussions of different circumstances when soft balancing was attempted but may not have succeeded. Success is not the same as the attempt. We know that hard balancing or economic sanctions do not always succeed. Yet states attempt these strategies for various reasons, including domestic pressures. The book discusses the Concert of Europe and the League of Nations, as well as Cold War and post–Cold War era cases. Other works exist on soft balancing in different regions such a Latin America, Central Asia, and Africa, showing the global relevance of this theory.

I disagree with Shifrinson’s contention that hard balancing is the dominant mode of US balancing toward China today. Yes, some amount of military buildup is taking place, with the aim of retaining US hegemony—and not purely for balancing or creating an equilibrium with China. No new hard balancing coalition has been formed yet (only the existing ones such as US–Japan and US–Korea, which are much weakened under Trump). China is pursuing its expansion in the South China Sea and the Indian Ocean, as well as the Belt Road Initiative, connecting trade routes to Europe via Central Asia and Africa. The new US QUAD partnership with Australia, India, and Japan is of a soft balancing variety.

In fact, the United States has responded tepidly to Chinese expansion, presenting a strong challenge to the balance of power theory. The “pivot to Asia” strategy was a limited hard balancing measure. This was very different from the manner in which previous rising powers were treated by established powers or in which the United States contested the Soviet Union during the Cold War. The US military buildup in the Indo-Pacific is not sufficiently balancing or deterring China’s expansionist behavior, because Beijing is playing an asymmetric, economic, infrastructure-based strategy to expand, and resorting to strategies such as wedging smaller powers to confront the United States’ traditional approaches. And Washington does not have strong answers yet.