When Americans want something that lies in another country, the consequences for that other country can be severe.
Even if they don't actually invade, they put a lot of pressure on lesser countries to behave as they want.
Canada, for instance, hasn't been invaded by the United States since 1812, but Ottawa has proved highly co-operative with Washington's desire to have access to our oil. We are America's Number 1 supplier.
Pressure for Canadian acquiescence in servicing America's apparently bottomless energy appetite is only going to get more intense, as fresh panic sweeps across America over skyrocketing oil prices and supply insecurity. Oddly, the Bush administration continues to flirt with the idea of making oil supplies even more insecure by launching a military strike against Iran.
All this turns the spotlight ever more on Canada as America's energy dream, nestled conveniently on top of the homeland, far from the roiling waters of the Persian Gulf.
Typical was a commentary on CNN's American Morning last week in which business correspondent Ali Velshi gushed about how Alberta's oil sands have more oil than Saudi Arabia, and most of it goes to the U.S. Velshi said that if daily oil-sands production were to rise from 1.5 million barrels to 4 billion or 5 million barrels, that would amount to "about a third of all the oil that the U.S. imports."
He noted that this Canadian treasure trove of oil could service U.S. needs for the next 70 years, possibly the next 150.
As American audiences are increasingly titillated by the idea that the oil sands could solve their energy dilemma, the window may be closing on what's left of Canadian decision-making power over our own energy.
Noticeably absent from the CNN report was any mention of the fact that the oil sands produce extraordinarily large greenhouse gas emissions, and plans to triple current output would be environmentally disastrous.
The future of the oil sands is one of the most important and contentious issues facing Canada, pitting concerns over global warming and the need to meet our international Kyoto obligations against the desire to make huge profits selling oil and to accommodate American interests.
There's an acute need for some sort of coherent national policy to deal with all this, to avert the looming environmental disaster while minimizing regional divisions and tensions with the United States.
Canada's policy vacuum only encourages the Americans to assume they can count on Canadian acquiescence to their energy dreams.
Of course, for years Ottawa has stubbornly refused to develop any sort of national energy policy, after Pierre Trudeau's efforts to increase Canadian energy independence self-sufficiency were soundly defeated by U.S. oil companies and the Alberta government.
(Trudeau also created a publicly owned oil company in 1975, but unfortunately Petro-Canada was privatized in 1991. Imagine if we had the option as consumers today of directing the exorbitant amounts we're obliged to spend on gas into the public treasury, rather than the coffers of Exxon or Shell.)
Now, with the urgent new realities of global warming, a strong government in Ottawa might have worked up the courage to take another run at developing a national energy policy. Sadly, however, at the helm these days is the Harper government, which clearly won't do anything that might annoy its base in Alberta or Washington.
Actually, the truth is we do have a national energy policy -- it's just that Canada isn't the nation that designed it.