Reviewed by: Peter Kikkert (), Sheridan CollegeIvan Head, a lawyer and civil servant who studied the evolution of Canada's Arctic maritime sovereignty policy and helped create the Arctic Waters Pollution Prevention Act (AWPPA), once commented that, step by step, fiber by fiber, the Canadian government had weaved a fabric of sovereignty in the north (175). In this detailed and well-written study, historian Adam Lajeunesse assesses the twists and turns involved in Ottawa's construction of this fabric for the Arctic waters over the century between 1880 and the 1980s, and identifies some of the holes that remain. In particular, Lajeunesse focuses on the evolution of Canadian thinking on three interconnected issues: how to define Canada's Arctic waters, how to legally and politically justify a claim to those waters, and how to advance an official claim on the international stage. In exploring these themes, he takes the reader on a journey through the historic legal thinking of Canadian officials as they tried to build a case for Canada's sovereignty over the Arctic waters, and ably explains the key ideas that have defined Canadian policy: from the sector principle, to historic internal waters and straight baselines, to the AWPPA and Article 234 of the 1982 United Nations Convention on the Law of the Sea. In charting a course through these legal developments, Lajeunesse highlights the complex interplay between law, diplomacy, and state practice that has shaped Canada's Arctic policy.In an excellent introduction that engages with the rich body of historical scholarship on Canada's Arctic sovereignty, Lajeunesse effectively situates his study in the literature. He takes a position between the two main opposing schools of thought on the development of Canada's Arctic policy. On one side are those scholars who believe that the government has been reactive and ineffective in its policy-making, and who argue that Ottawa should have attained formal recognition of Canada's Arctic maritime sovereignty long ago. On other side are those who argue that External Affairs developed a clear and consistent policy to gradually strengthen Canada's claim while avoiding disastrous political and legal challenges. In his study, Lajeunesse adds nuance to the arguments of both schools by highlighting Ottawa's failure to unify thinking across the political and bureaucratic spheres, which resulted in several waves of inaccurate, inconsistent, and damaging public pronouncements by Canadian politicians, even as civil servants worked to construct a strong legal case behind the scenes.Much of the legal subject matter covered by Lajeunesse has been thoroughly explored by international lawyers, including eminent scholars Donat Pharand and Donald M. McRae. Nevertheless, the new archival material that Lajeunesse draws upon--much of it uncovered through access to information requests--affirms the important role that historians can play in unpacking legal developments as they unfolded over time. Rather than applying current legal standards, assumptions, and desires to analyze past practices, and assessing whether these support Canada's current position--as much legal scholarship does--Lajeunesse's study respects the state of maritime law at the time when decision-makers weighed options and chose their approach. He shows how the legal thinking of historical actors unfolded in response to contemporary legal and political developments, and highlights the different variables that shaped decision-making, whether it be Cold War politics or concerns over evolving maritime boundaries in Canada's southern waters. …