Canada’s "Polite No" to SDI: A Question of Sovereignty?

Brunet, Luc-André (2023). Canada’s "Polite No" to SDI: A Question of Sovereignty? In: Brunet, Luc-André ed. NATO and the Strategic Defence Initiative: A Transatlantic History of the Star Wars Programme. Cold War History. London: Routledge, pp. 129–145.



This chapter examines the Canadian government’s reaction to the Strategic Defence Initiative and its impact on bilateral relations between Ottawa and Washington. Given Prime Minister Brian Mulroney’s priority of improving relations between the two countries, his decision for Canada not to join the SDI research programme appears puzzling. Previous studies have suggested that Canada’s ‘polite no’ was motivated by a desire to defend Canadian interests and sovereignty, as well as Mulroney’s misgivings about the possibility of an arms race in outer space. By contract, this chapter, based on newly declassified sources in Canada, the United States and the United Kingdom, argues that Mulroney’s overriding priority when considering SDI was in fact closer economic cooperation with the United States. Conscious of public criticism within Canada of pursuing too close a relationship with the United States, Mulroney used his public rejection of SDI as a politically convenient means of demonstrating his defence of Canadian sovereignty days before unveiling his priority: free trade negotiations with the United States. As such, Canadian assessments of whether to participate in the SDI research programme had surprisingly little to do with broader strategic considerations.

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