Becoming Sovereign Review by Matthew S. Weinert Department of Political Science and International Relations, University of Delaware Contracting States: Sovereign Transfers in International Relations. By Alexander Cooley and Hendrik Spruyt. Princeton, NJ: Princeton University Press, 2009. 232 pp. $24.95 (ISBN-13: 978-0-691-13724-7). Property (and its adjunct use rights) is as central to sovereignty as authority (and its adjunct control rights). Willem Riphagen (1975) resurrected the medieval legal concept of usufruct (use) rights to understand the diverse, functionally-ori- ented sovereignty claims made by multiple nations over the Spitsbergen Archi- pelago in the Arctic Ocean. Fowler and Bunck (1995) furthered the claim in spirit if not in language by differentiating between sovereignty as a chunk and sovereignty as a basket. If the former reiterated an ideal-type Westphalian logic of exclusive control and ownership, then the latter envisioned alternative arrangements whereby sovereignty (or more appropriately its various use and control rights and functions) could be disaggregated and re-allocated in diverse kinds of arrangements. Stephen Krasner (1999) articulated four distinct kinds of sovereignty, and thus strongly suggested that the exclusivity and absoluteness associated with sovereignty needed to be significantly relaxed if not laid to rest. Alexander Cooley and Hendrik Spruyt’s exciting, engaging, and eminently intel- ligent new book adds a distinct richness and depth to this kind of sovereignty lit- erature. Scholars interested in sovereignty, international relations history, and IR theory will find this book particularly useful. Contracting States focuses on the allocation of use and control rights that result in hybrid governance arrangements in three distinct issue areas: decolonization and imperial disengagement, negotiations regarding overseas US military basing arrangements, and regional integration in Europe and North America. In each case, the authors contend that incomplete contracting theory, more than realism or constructivism, helps clarify how and why states disaggregate usage rights over specific assets and grant them to other states, and design inter-state institutional structures that compromise the exclusive, Westphalian logic of sovereignty. By incomplete contracting, the authors mean ambiguous contracts which ‘‘arise from the imperfections and transaction costs generated by the contracting envi- ronment that prevent actors from specifying complete contracts’’ and which in the end ‘‘delineate general principles and broad goals’’ to be redefined later in time rather than assert more specific sets of rights and obligations (p. 8). The clearest examples of incomplete contracts in the book are the early European regional integration agreements, based as they were on broad principles and lacking a high degree of specificity. Complete contracts, in contrast, ‘‘describe and specify the full array of responsibilities and obligations of the contracting parties…[and] anticipate every possible future contingency’’ (p. 8). According to the authors, the North American Free Trade Agreement (NAFTA) clearly reflects a complete contract insofar as its extensive and highly detailed provisions foreclosed many possibi- lities and avenues of development that were left open by the European agree- ments. While incomplete contracts provide for renegotiation and flexibility Ó 2010 International Studies Association International Studies Review (2010) 12, 325–327