Historically, national borders have evolved in ways that serve the interests of central states in security and the regulation of trade. This volume explores Canada–US border and security policies that have evolved from successive trade agreements since the 1950s, punctuated by new and emerging challenges to security in the twenty-first century. The sectoral and geographical diversity of cross-border interdependence of what remains the world’s largest bilateral trade relationship makes the Canada–US border a living laboratory for studying the interaction of trade, security, and other border policies that challenge traditional centralized approaches to national security.

The book’s findings show that border governance straddles multiple regional, sectoral, and security scales in ways rarely documented in such detail. These developments have precipitated an Open Border Paradox: extensive, regionally varied flows of trade and people have resulted in a series of nested but interdependent security regimes that function on different scales and vary across economic and policy sectors. These realities have given rise to regional and sectoral specialization in related security regimes. For instance, just-in-time automotive production in the Great Lakes region varies considerably from the governance of maritime and intermodal trade (and port systems) on the Atlantic and Pacific coasts, which in turn is quite different from commodity-based systems that manage diverse agricultural and food trade in the Canadian Prairies and US Great Plains.
 
The paradox of open borders and their legitimacy is a function of robust bilateral and multilevel governance based on effective partnerships with substate governments and the private sector. Effective policy accounts for regional variation in integrated binational security and trade imperatives. At the same time, binational and continental policies are embedded in each country’s trade and security relationships beyond North America.

Canada and the United States share a border that spans several of the world’s major watersheds and encompasses the largest reserves of fresh water on the planet. The border that separates these two neighbors is political, but the natural environment is a matter of common concern. In recent years, dramatic changes have taken place in the political and environmental landscapes that shape the conversations, possibilities, and processes associated with the management of this shared interest. More than ever, Indigenous populations are recognized to be a necessary part of negotiations and decision-making regarding matters ranging from pipelines to the protection of endangered species’ habitats. Globalization and, in particular, the continuing elaboration of a transnational conversation and architecture for addressing issues related to climate change have ramifications for Canada-US transboundary issues. The contributors to this volume examine the state of the existing transboundary relationship between Canada and the United States, including the governance structures and processes, the environmental impacts and adequacy of these structures and processes, and the opportunities and obstacles that exist for reform and improved outcomes.