'A Justifiable Obsession' traces the evolution of Ontario's relationship with the federal government in the years following the Second World War. Through extensive archival research in both national and provincial sources, P.E. Bryden demonstrates that the province's successive Conservative governments played a crucial role in framing the national agenda – although this central relationship has received little attention compared to those that have been more volatile. As such, Bryden's study sheds light on an important but largely ignored chapter in Canadian political history. Bryden focuses on the politicians and strategists who guided the province through the negotiation of intergovernmental economic, social, and constitutional issues, including tax policies, the design of the new social welfare net, and efforts to patriate the constitution. Written in a lucid, engaging style that captures the spirit of the politics of postwar Canada, 'A Justifiable Obsession' is a significant contribution to our understanding of Ontario's politics and political culture.