Maintaining our borders protects our access to key resources - oil, gas, fish - as well as well as reinforcing our control over the environmental stewardship of these resources. While some of the territories in question are not core to the Canadian polity, the legal and political arguments made to maintain them are the same ones that allow Canadian stewardship of the Gulf of St. Lawrence, the Georgia Strait and the Strait of Juan de Fuca near Vancouver, and the Bay of Fundy.
4. Strong international institutions to counterbalance U.S. hegemony
Living next to an elephant, as Canadians do, we natural move to support strong international institutions that can act to constrain the United States. Canada is often described as a "middle power." This has been defined as meaning "All middle powers display foreign policy behaviour that stabilizes and legitimizes the global order, typically through multilateral and co-operative initiatives."
Basically, there are "great powers" in the world, like the United States, China and - arguably - countries like Russia or India. There are regional powers, who begin to dominate a sector of the globe, like Brazil or South Africa. There are minor states who tend to get pushed around by the other two categories. Then there are "middle powers." These tend to be stable, democratic, stable, egalitarian, and distinct from the great and small powers.
Canada is a textbook "middle power" and as such, follows the textbook on being a middle power. We attempt to strengthen international institutions where "middle powers" can use our soft power influence and reason to preserve international order through gradual reform, rather than radical global change.
Pearsonian diplomacy, Peacekeeping, the United Nations and all the other Canadian touchstones in foreign policy are all about strengthening international order through institutions.
5. Open borders with the United States
Free trade with the Americans is a policy Canada long rejected and only recently endorsed. The reason for that acceptance was the successful implementation of the other four steps of our strategy. With independence from the Americans secure, the nation relatively unified, our territory secure (at least at the core) and strong international institutions like the WTO established, free trade is a far more reasonable policy than it would have been in the 19th century.
Open borders ensure access to the market where the vast majority of our exports go. Our domestic markets are simply too small and too geographically dispirit to allow for a high tariff policy unless we are willing to compromise our standard of living. The alternative to U.S. markets is far more expensive shipping of goods to Europe or Asia, or the marketing of services to nations with different time zones and languages.
As free trade becomes more ingrained, even minor shifts in border policy can have large impacts. The recent move to require American citizens to provide a passport when reentering the country from Canada had a severe impact on services in border communities on the Canadian side.
A border closure would wreck havoc on the Canadian economy. Autarky is not a good idea in a country of our size and density, and attempts to reduce our opportunities to trade with the U.S. will translate directly and quickly to our standards of living.
However, free trade is a policy we can afford only so long as the other elements in our strategy are stable. If the alternative is the loss of independence or loss of territory, we could see free trade sharply decline.
These elements of the Canadian grand strategy can be seen in government actions throughout our history.
Canada was formed to fend off a growing threat of invasion from the United States. The decision was made to join together to ensure our political independence, the first step of our strategy.
John A. Macdonald's first term saw the use of force to end the Red River Rebellion - addressing the second element of policy unity - and the purchase of Rupert's Land - the expansion and consolidation of our territory.
Patriotic membership in the British Empire served to strengthen our first four strategic goals, until after the First World War, when the declining Empire and rising Canadian Nationalism demanded a new course.
Canada's leadership in the post-war international community was all about the fourth element: creating the United Nations, NATO, WTO and G20 to produce counterbalances to growing American power.
What is so interesting about our history is our achievement of the fifth stage in our strategy, and the ability to now engage the Americans as equals in trade without fear of cultural or political colonization.
Certainly, this is only a quick sketch of what Canada's grand strategy may be, and I invite thoughts on alternatives.