Why has state building in Myanmar's borderlands with China and Thailand failed? In his newest book, Enze Han builds on his research on the international elements of ethnic identity formation in China to argue that the answer is as transnational as it is domestic. Han proposes a “neighborhood effect” to argue that power asymmetries between neighboring states can result in uneven development in their respective borderlands (p. 5). The concept depends on two aspects of international relations that, combined differently, produce different outcomes for state and nation building: power asymmetry and relations between neighboring states.

Regarding state building, Han's argument can be expressed in four if/then scenarios: (1) if (power asymmetry) + (adversarial relations), then the strong state meddles in the weaker state's borderlands; (2) if (power asymmetry) + (amicable relations), then the strong state only engages in economic manipulation of the borderlands; (3) if (power symmetry) + (adversarial relations), then the borderlands become militarized; (4) if (power symmetry) + (amicable relations), then the states peacefully coexist (p. 32). Demonstrating how these scenarios unfolded from the sixteenth century to the 2010s occupies most of the book's brisk 163 pages (excluding endnotes).

Nation building—creating “an inter-subjective understanding of mutual belonging” through, for example, a common language or acceptance of a national identity alongside minority identity—is concurrent with state building, but, Han argues, it is a separate process still subject to the neighborhood effect (p. 5). The key factors are power asymmetry, treatment of minority groups, and the presence or absence of an “external kin state” when ethnic groups exist on both sides of the border (p. 34). An example of an external kin state is Thailand in relation to the Shan people in Myanmar. The dominant ethnicity in Thailand (Thai people) and the Shan people were both part of a historical network of ethnic Tai principalities (p. 38). The Kachin people in Myanmar and the Jingpo in Yunnan Province, China, are an example of cross-border ethnic kinship without an external kin state (p. 129). Han's argument functions as follows: (1) if (power asymmetry) + (external kin state), then the strong kin state will support ethnic movements in the neighboring state, hampering the development of national identity; (2) if (power asymmetry) + (no external kin state), then the ethnic minority groups will resist national identity by comparing conditions on either side of the border. This is the bolder of Han's two neighborhood effect claims, but it is only directly taken up in a single chapter.

The analysis begins with tributary relations between, on the one hand, Tai principalities in southern Yunnan, northern Burma, and Siam and, on the other hand, Qing, Konbaung, and Chakri rules. By the late nineteenth century, confrontations with British imperialism resulted in a loss of Burmese control over northern kingdoms, while in Siam, British commercial interests prompted Bangkok to strengthen control in the north. With British and French colonies on its southern borders, the Qing also consolidated control over Yunnan. In Burma, the relative autonomy given to groups like the Shan and Kachin by the British had long-lasting implications for state and nation building. Qing and Chakri systems for administering these regions were repeated under the Republic of China and after the end of absolute monarchy in Thailand—continuing the consolidation of state control until the Japanese invasion in World War II.

Following the Chinese revolution, several thousand members of Chiang Kai-shek's Guomindang Army fled into Shan areas of Burma, where divisions between ethnic minorities and the majority Bamar ethnicity that had been exacerbated under British rule prevented state consolidation after independence. Chinese Communist Party concern over Guomindang troops in Burma prompted a campaign against counter-revolutionaries in Yunnan and increased efforts to make accommodations for local ethnic minority leaders along the border. For Burma, however, Guomindang troops destabilized the region by promoting Shan separatism and amplifying opium production to support operations. As Burma appealed to the United States to help get rid of the Guomindang Army, Thailand successfully pitched itself as a stronghold for anticommunism.

These experiences impacted each country's ability to curtail communist insurgency from the 1950s to the 1980s. After the Cold War, Thailand and China both benefited from relations with the United States, while US sanctions forced Myanmar to depend on China for trade and diplomatic protection. China shielded Myanmar from United Nations sanctions while cutting deals with separatist groups along the border for timber and jade. Han argues that Myanmar's continued ethnic conflicts are due in part to, e.g., Kachin people preferring the lives of Jingpo people across the border in China or Thailand's previous “buffer zone” border policies, which allowed Shan separatists to establish bases within Thailand and receive support from the Thai government indirectly through Guomindang Army remnants (pp. 130–31).

The book is an excellent primer on the history of how these states have exercised power in their shared borderlands. Han's “neighborhood effect,” however, requires the reader to accept that states and ethnicities operate like corporatized individuals, always acting rationally toward their own interests without internal contradictions. Many readers will find this an outdated premise. Further, specialists in any one country are unlikely to find much new. Finally, although attention should be paid to the interactions between these states in understanding the history of their borderlands, it is clear from Han's own evidence that British imperialism and US Cold War interventions had an equal, if not larger, impact on this region than can be accounted for with the state and nation building schematics presented here.