agenda of Canadian national policy. 4
             Any analytical tool that claims to provide both insights into the future and bring clarity to the present is appealing, but the relevance and accuracy of such devices often fade over time. Yet Sutherland's invariants continue to draw the attention of analysts 40 years after they were first postulated, suggesting some continuing relevance to Canada's security situation, despite a dramatically different global context. This essay will argue that Sutherland's cold war analysis of Canadian geography, economics, and broad national interest provides insights that are as relevant today as they were 40 years ago and that continue to offer stable policy foundations for Canada.
             Taking each invariant in turn, this analysis will examine Sutherland's key deductions in their original context before demonstrating how they remain representative in today's post-Cold War and post 9/11 environment.
             Canada's geographical situation is defined by its vast landmass, surrounded by three oceans, bordered by the US, and inhabited by a small, highly urbanized, and unevenly distributed population. Whilst obvious, these geographic facts have always presented unique challenges to those responsible for the defense and security of Canadian territory.5 Based on the safe assumption that Canada's southern neighbor would remain at least a great power for the foreseeable future, Sutherland made three fundamental deductions regarding Canada's geography. Firstly, the US would be bound to defend Canada from external aggression, almost regardless of whether or not Canadians wished to be defended.6 Secondly, it would normally be in Canada's interests to play its part in the defense of the US and thirdly he cautioned that a great power like the US would take whatever action was necessary to maintain its security. In other words, Canada's geographical position combined with the likely longevity of US power produced the benefit of an ...