Most U.S. observers would be surprised by the vitality and engagement of the national postal system in the political and economic spheres elsewhere in the world. In no other country is the postal system as densely and consequentially woven into the body politic as in Japan, particularly during the twentieth century. Maclachlan, in an engagingly written and often entertaining book, recounts both the small and significant, visible and invisible ways that Japan's postal system permeates society. More centrally, once that narrative is established, she offers a compact, though nuanced, explanation for why and how the Koizumi reforms of the 2000s ultimately transformed (and are still transforming) the relationship between the postal system and electoral politics.

While focused on Japan, this book employs a comparative historical institutional analysis to explain how the postal system became so embedded in the social lives of ordinary citizens. Japanese nation-builders during the Meiji period were greatly influenced by foreign institutions and sought to emulate them in their efforts to rapidly modernize the country. Maclachlan lucidly argues that emulation of foreign institutions and practices are highly conditioned by domestic factors at the time they are adopted. Policymakers' intentions are not always borne out and unintended consequences emerge, with lasting and path-dependent effects. This point is made most clearly in her explanation for how postmasters in Japan, in marked contrast to those in Britain, became powerful mobilizers for national elections linked closely with conservative political parties.

Timing and sequencing of national development made the difference. In Britain the modern state was already in place when the postal system was established. Consequently, the development of postal networks there was primarily an administrative and nonpoliticized matter for the state. In contrast, Japan's postal system was developed simultaneously with the creation and expansion of the modern state. Vitally important to Japan's modernization was the adoption of a postal savings system (and later postal life insurance), which flowered in Japan to an extent not seen elsewhere. Patriotic postmasters functioned as an important arm of the state in mobilizing private savings to first provide capital for Japan's catch-up economic and industrial development, and then finance the country's imperial and militarist pursuits.

The highly centralized postal bureaucracy selected men of note and commissioned them as postmasters. Their positions were locally prestigious, and many of them subsequently became hereditary posts. Maclachlan vividly describes the vital interface that the postal system provided between citizenry and state in the Meiji, Taisho, and Showa periods. It reached far beyond mail and parcel delivery into social welfare and community engagement. A telling example is the himawari system that employs mail carriers to check in on the elderly and infirm while on their rounds. What emerges and then institutionalizes is a postal system characterized on the one hand by competence, convenience, and reliability, and on the other, a moral standing that is personified by locally respected postmasters.

The story of the postmasters' growing political influence, organization, and mobilization powers is inextricably linked to the post-World War II rise of Tanaka Kakuei's political machine, and the institutional design of Liberal Democratic Party (LDP) dominance that relied on multimember electoral districts and rural votes. Little surprise, then, that as the 1955 System slowly disintegrated so did the solidarity and influence of postmasters. How then, she asks, does this help to explain the enormous transformation that occurred under Koizumi's leadership?

Here, Maclachlan shifts gears to explain systemic evolutionary change punctuated by the entries (and exits) of key political actors. The more proximate grounds for the success of Koizumi's postal reforms are well-covered by other scholars. These include the impact of the 1994 electoral system changes that replaced multimember districts with “winner-take-all” single-member districts, and also changes to the way in which the LDP president was selected, which reduced the appeal of special interest candidates while favoring those who could appeal to a broader electorate. The novel contribution of this book is that it demonstrates how these proximate factors interacted with much longer-term transformations that occurred endogenously among the postmasters, the postal workers, the political parties, and the ministries that governed postal affairs.

Particularly useful is the description of how long-festering resentments between and among these actors became highly politicized in postwar society. Maclachlan offers a detailed account of how old conflicts met new channels of voice and interest mobilization in the 1950s. The roots of the Koizumi reforms go deep: it was the latest in successive attempts in the postwar period to reform commissioned post offices (and more generally, the bureaucracy). Each such attempt resulted in institutional changes that altered the game for the next set of reform efforts. Koizumi, while establishing new institutions of his own, was able to leverage the political changes made by predecessors to push through the legislation that would ultimately break up the postal system, and break the hold that postmasters and LDP politicians had on each other.

Students of modern Japanese politics will find this a fairly convincing narrative that is well researched and employs numerous interviews and Japanese archival sources. The book's use of archival photographs from the Communications Museum in Tokyo is particularly engaging. Those who are curious about the uniquely central role of postal savings in Japan's economic development will also find this book to be informative. The repercussions of the reforms that Maclachlan traces back historically are still felt in Japan's electoral politics and financial circles. This book goes a long way towards explaining why.