In the last few decades, historians of migration have increasingly zoned in on exclusion, rather than inclusion, as the defining feature of United States federal policies on immigration. This is evidenced by the fact that while immigration laws in the early twentieth century facilitated the arrival of vast numbers of Europeans to the United States, the same laws raised significant barriers against migrants from Asia, and later against migrants from Eastern Europe. This emphasis on exclusion has continued with studies on deportation, as well as the impact of immigration policies on the migration of women, LGBTQ people, and those with disabilities.

Ben Herzog's book continues this focus on exclusion by stretching the field of analysis to include citizenship. What is unique about Herzog's approach is that his study does not focus on the usual logic and practice of preventing immigrants from obtaining citizenship that have preoccupied historians for so long. Rather, it focusses on the state's desire to deprive existing citizens of their lawful citizenship, i.e. efforts to revoke citizenship. This exclusion haunts immigrants well after they have become citizens, sometimes even a few generations on. The defining questions of Herzog's book, thus, are as follows: “Why do states take away citizenship from their subjects? When do states expatriate their citizens and with what justification?” (2). Herzog limits his analysis to the United States and to looking at the evolution of the practice of revoking citizenship from colonial times to the current War on Terror.

Most readers would find the very idea of citizenship as revocable to be surprising. So how did it take root in the American polity? As Herzog explains, citizenship was not always transferable. Early British common law carried the notion of “perpetual allegiance” as opposed to the “idea of citizenship as consensual membership” (29). Despite the American Revolution and ongoing naturalization of settlers into American citizenship, the question whether individuals had the power to cut ties with their country of origin and be universally recognized as American citizens remained. To remedy this state of affairs, Congress passed the Expatriation Act of 1868, which for the first time recognized an individual's “right of expatriation from another country to the United States” (35). The Expatriation Act not only declared the United States a sovereign entity willing to assert its powers on behalf of its citizens, but also legitimized the notion that individuals could choose their national allegiance.

Passage of the 1868 Expatriation Act, and its break from previous conceptions of citizenship as untransferable, contributed to the notion not only that the ability to grant or revoke citizenship was a crucial test of sovereignty, but also that citizenship was a conditional relationship between the citizen and the state, subject to revocation by either party. The first statute to explicitly legislate conditionality and to lay down revocation laws was the Naturalization Act of 1906, followed a year later by the Expatriation Act of 1907 (the most famous provision of which was to expatriate American women for marrying foreigners), and then by further legislation both before and after the Second World War – the Nationality Act of 1940 and the Immigration and Nationality Act of 1952 – to regulate citizenship. As a result of these laws, through the early to mid-twentieth century, US citizens could lose their citizenship by committing acts such as voting in a foreign country, naturalizing abroad, serving in the armed forces of another country, and so on. These legislative efforts were eventually unraveled by a string of Supreme Court decisions in the 1960s which shifted the terms of the conditional relationship between the citizen and the state – loss of citizenship became reliant on the citizen's “intent” while committing an expatriating act.

Herzog traces these legislative developments and argues that expatriation was “an internal regulatory practice,” one “contingent on particular political or practical circumstances,” as well as “international relations” (4). Thus Herzog looks at the United States’ attempts to enter into treaties with other nations to regulate citizenship, as well as consular dilemmas regarding the protection of citizens abroad. In addition to providing a historical perspective, Herzog also frames his questions sociologically, arguing that expatriation can be understood as “an attempt to regulate and enforce the national world order,” the “hegemonic geopolitical perception” that the world is divided into “distinct national entities” (4). In the United States particularly, expatriation, Herzog argues, served as a means to deter dual citizenship and to guarantee a citizen's perpetual allegiance to one country. Dual citizenship and the perceived threat it posed to the “national logic” thus was one of the main driving forces behind expatriation laws. More recently, this threat to the national logic and expectation of unconditional allegiance has reemerged in efforts to expatriate citizens involved in the War on Terror.

What Revoking Citizenship gains in breadth, however, it loses in depth. Other than brief descriptions of individuals involved in Supreme Court cases or in appellate reviews, one rarely hears the voices of expatriated individuals and gets little sense of the personal or social impact of expatriation. In addition, other than on rare occasions, the bureaucratic and surveillance mechanisms that implemented expatriation laws and led to the initial loss of citizenship are largely hidden from view. The book is also riddled with an inordinate number of typos which can prove distracting. Nevertheless, Herzog's book is a valuable study of the historical evolution of expatriation in the United States, a topic that as yet remains understudied.