International law has not yet satisfactorily delineated the legal effects of State succession, especially on commercial obligations. Assuredly, a number of approaches have been suggested. One approach is tabula rasa, namely that the succeeding State inherits none of the obligations assumed by its predecessor: the slate is wiped clean. Another approach is universal succession, namely that the succeeding State inherits all of the predecessor's obligations. A third approach, which resonates in recent practice, is continuity. The trend towards continuity differs from universal succession in that it recognizes the inequities that can result from boilerplate imposition of the obligations incurred by predecessors and, accordingly, welcomes exceptions and limitations thereto (e.g. in cases of succession through decolonization).

Notwithstanding certain developments within the law, many issues remain unresolved. Traditional theses regarding State succession, when applied to commercial matters, remain ill-fitting. What is more, satisfactory conceptual approaches to what the law of State succession in commercial obligations should look like are under-explored.

Dr Tai-Heng Cheng steps into this breach. In State Succession and Commercial Obligations, Dr Cheng, Associate Professor at New York Law School, energizes the discussion and addresses some of these lacunae. Insofar as successions have occurred even in the short interlude since State Succession and Commercial Obligations went to press, Cheng's work is deeply topical.

Cheng achieves three important goals in this erudite volume.

First, he reviews extant positive law. In particular, he sets out the details of two important international instruments: the Vienna Convention on Succession of States in Respect of Treaties of 1978 (in force) and the Vienna Convention on Succession of States in Respect of State Property, Archives, and Debts of 1983 (not in force as of the time of writing). His review is complemented by a detailed treatment of the International Law Commission sessions that preceded the elaboration of these international instruments. Neither instrument is fully geared to commercial obligations. However, both instruments contribute to the substantive law. (Both are included in the appendices to State Succession and Commercial Obligations, thereby promoting ease of reference.)

Second, Cheng surveys State practice. He does so through a sophisticated review of five case studies of actual, and recent, State succession: East Timor, the former Yugoslavia, Czechoslovakia, the Soviet Union, and Hong Kong and Macau (considered jointly). As Michael Reisman notes in his foreword to State Succession and Commercial Obligations, these case studies are the “heart” of the book (p. x). Cheng examines the role of international organizations, national governments and domestic Courts. The scope of materials considered and the maturity of the review render these five chapters of deep salience to practitioners advising on matters of State succession, not to mention area specialists who seek more specific research on a particular case study. Cheng's review demonstrates the operational influence of continuity as a governing principle.

Third, Cheng engages with what the law of State succession should look like. He serves up a number of normative principles that, in his estimation, ought to animate future directions taken by the law. These recommendations are both academic as well as applied. They will serve of great use to practitioners and policymakers. Cheng identifies five “conditioning factors” that academic and practising lawyers could turn to so as to clarify the law of State succession to clients concerned with commercial obligations (p. 382). The conditioning factors are (1) the density of international relationships; (2) the relative power and authority of decision-makers; (3) the minimum requirements of the right to self-determination and other human rights; (4) the presence or absence of supervening geopolitical factors and (5) implicit or explicit collective decision-making among international decision-makers (p. 382). In this regard, Cheng places himself within the continuity camp, although he espouses a continuity that focuses on pertinent cooperation, not on a “balance sheet of continued or discontinued obligations” (p. 386).

Cheng's contribution could have remained deeply influential even were he to have stopped after the second of his three goals. After all, there is limited scholarship that offers a summation and synthesis of the law and practice of State succession. But, in the spirit of ambitious and engaged scholarship, Cheng takes the reader well beyond. In so doing, he also foreshadows important issues that the law of State succession shall have to address in the future. For example, how should the law treat those obligations incurred by criminal States which have transitioned to law-abiding regimes? How should the law of State succession deal with regimes that emerge from the tumult of conflict, State failure or systemic human rights abuses?

Cheng takes a purposive approach to State succession. For him, State succession includes regime change (p. 33); he collapses the distinctions between State and government succession. He posits that “[s]uccession occurs when a state fundamentally changes its structures of power and authority, and an authoritative international response is needed to manage disruptions to international arrangements that may result from that change” (p. 3).1 Insofar as the purpose of the law is to “promote global order and development,” Cheng sees little merit in drawing “doctrinal distinctions between state and government succession” (p. 4).

He also takes a purposive, and holistic, approach to which obligations ought to continue. He places State succession outside of a narrow context and recognizes the plurality of actors that are affected by successions. Instead of thinking of “continuity of specific obligations”, Cheng pushes us to think of “continuity of cooperation”, (p. 6). By “continuity of cooperation”, he means an approach “in which commercial obligations are tools for cooperation that can be strengthened, adjusted, or replaced to promote cooperation according to the individual circumstances of each succession” (p. 6). As the density of relationships in international law thickens, so too does the need for an invigorated understanding of continuity. That said, Cheng also recommends limiting the scope of continuity in a number of important ways. One such way is by paying attention to human rights concerns. For Cheng, “[w]here people living in a territory that undergoes succession were oppressed and excluded from their governance, or where their ruling elite entered into unjust international arrangements, international decision makers may align themselves toward the discontinuity of unjust obligations” (p. 393).

Notwithstanding the many strengths of this book, it is not without certain shortcomings. For one, Cheng–perhaps in a subsequent work–might contemplate more specific recommendations, whether conceptual or practical; he might do more to separate lex ferenda from lex lata. He might consider whether the law of succession in terms of commercial obligations may take different forms depending on the nature of the succession. Although Cheng recognizes the different forms that succession can take (pp. 50–51), he does not flesh out whether this diversity, in turn, should trigger diversity in terms of the form of the substantive law, in particular, any predisposition towards continuity. It may well be that succession of commercial obligations is simply not an area of international activity suitable for firm rules.

Moreover, Cheng might integrate the law of State succession more closely with other substantive areas of international law, in particular, international trade law (although he does effect some linkages with international investment law). Readers may also remain curious as to the interface between internationalized modalities and national and local approaches to succession, which might entail turning to complex questions of comparative legal analysis.

That said, State Succession and Commercial Obligations has done the international community a great documentary and theoretical service, and the future research paths it invites merely attest to the force and dynamism of this project that Cheng has so skilfully brought to fruition.

See also p. 37: “State succession is not limited to changes in the international legal personality of a state, but includes any fundamental reorganization of a state that triggers international claims concerning preexisting commercial obligations and requires an international response.”