measurements of the balance of power can also mislead. The Correlates of War index contains six indicators of national capabilities: energy consumption, iron and steel production, military expenditures, military personnel, total population, and urban population.7 These indicators are fixed: the index treats them as valid measures of national power from the nineteenth century to the present. In reality, what defines the balance of power has evolved over time. To give only one example, steel production once attested to a nation’s overall level of economic development and war-making potential but long ago ceased to be a cutting-edge industry or a vital military input. The same applies to all indicators in the Correlates of War index except a state’s military expenditures.
To accurately capture the balance of power requires historical context. From the late nineteenth century to the present, three indicators of national power have remained relevant: a nation’s economic output, international trade, and military expenditures. Other indicators of national capability speak to the balance of power at specific junctures. In the pre-World War I period, observers looked to steel production and warship tonnage when evaluating the balance of power. The interwar years saw first-line aircraft join these two indicators as a period-specific measure of national capabilities. As the Cold War emerged, possession of the atomic bomb loomed large in contemporary assessments of power balances. Today, spending on research and development (R&D), along with GDP, international trade, and military expenditures remain seen as indicators of national strength. Table 1 summarizes how the defining characteristics of the balance of power have varied over time.
Table 1: Balance of Power
| Key indicators | ||
| Period | Type | |
| All | GDP International trade Military expenditures | |
| Prewar | Steel production Warship tonnage | |
| Interwar | Steel production Warship tonnage First-line aircraft | |
| Early Cold War Present | Atomic bomb R&D spending |
This century-plus span is rarely amenable to precise benchmarks that demarcate when changes in the balance of power amount to a state’s rise. While a state’s share of key capabilities should expand relative to the share of the democratic power, there is no clear-cut threshold marking the start of a power transition. The benchmark this book uses is a shift in the distribution of capabilities along multiple dimensions, with at least one dimension an enduring indicator of national power. The gap between the democratic power and the other state should narrow over time, though it need not close entirely.
The Balance of Perceptions
The balance of perceptions presents a different sort of measurement challenge. Perceptions of another state’s rise usually take the form of a comparison, with democratic leaders expressing concern about their country’s loss of preeminence going forward. To the degree that such concerns exist within a democratic elite, they are chronicled in public speeches, government documents, private correspondence, memoirs, newspapers, and magazines.
Various statements would indicate that democratic leaders worry about their country’s relative decline. Most explicitly, they could project that another state will overtake their own as the leading regional or global power. They could also anticipate a loss of preeminence in a more circumscribed area. On the economic side, this could include relative size of GDP, dominance of major export markets, or technological leadership. On the military side, democratic leaders might worry about a loss of military superiority, the advent of parity in conventional or nuclear capabilities, or a changed balance of power in a specific region.
In a democracy, the balance of perceptions hinges on mainstream elite opinion. If a handful of prescient pessimists foresee relative decline but democratic leaders as a whole express confidence about their nation’s prospects compared to another power, the balance of perceptions remains unmoved. For a shift to occur, democratic elites across bureaucratic and partisan lines should articulate concern about a diminishment of their state’s dominant position. Together with a change in the balance of power, this transformation of perceptions marks the moment when a democratic state begins to confront a fateful transition.
Identifying Cases
Together, power and perceptions determine the universe of cases relevant to the book. This universe encompasses “hegemonic transitions” where a democratic power’s global dominance comes under pressure from an ascendant state. Great Britain before World War I and the United States after 1945 have held international positions that approached hegemony. The book examines British strategy toward the emergence of the United States and Germany at the turn of the twentieth century, America’s approach to the Soviet Union’s postwar ascendancy, and the ongoing U.S. response to China’s rise. These cases feature changes in the balance of power and the balance of perceptions.
However, the criteria that define fateful transitions point to a broader set of cases than these four. Although its commercial and maritime primacy had faded, Great Britain during the 1930s was still a pivotal democratic state. Nazi Germany’s upending of a balance of power that favored Great Britain falls squarely within the universe of cases. So does China’s recent eclipse of Japan, the most influential democracy in East Asia. Both of these cases feature a reversal in the bilateral distribution of capabilities, and perceptions of a sharp power inversion by democratic leaders.
Power and perceptions limit the universe of cases to these six. British strategy toward czarist Russia and Meiji Japan, U.S.-Japan and Anglo-Soviet relations during the interwar period, and U.S. policy toward Japan in the 1980s have some resemblance to fateful transitions, but ultimately each historical juncture fails to meet one or both of the criteria set out. These cases were considered but ultimately omitted.8 The argument advanced by the book does not necessarily pertain when democratic leaders confront—or perceive—only limited fluctuations in the balance of power.
Democratic Strategies
Four strategic options—appeasement, integration, hedging, and containment—encompass the full range of policies that democracies have historically embraced as they navigate power transitions. These strategies vary widely in terms of the resources required and the actions involved. They do not capture polices that, while potentially effective, have no historical precedent, such as democratic leaders waging preventive war against a rising state or comprehensively encouraging an emerging power’s political liberalization.9
Appeasement
A democracy can appease a rising state. The historian Paul Kennedy classifies appeasement as a strategy designed to avert armed conflict by “admitting and satisfying grievances through rational negotiation and compromise.”10 Stephen Rock in his book Appeasement in International Politics presents a similar definition—a “policy of reducing tensions with one’s adversary by removing the causes of conflict and disagreement”11 He adds that appeasement may include mutual accommodation, but the appeaser takes the “initiative in offering inducements and will ultimately make greater sacrifices than its opponent.”
Both Kennedy and Rock provide for a relatively expansive definition of appeasement. In any instance of international negotiations, the final outcome may be uneven, with one party making more concessions than
