A British Alaska and North American oil supply

How much would British possession of Alaska change the United States?

Canada would gain a larger role in US imported oil, while Texas, the Gulf of Mexico, and other domestic sources would preserve substantial American production.

The counterfactual gives Alaska to Britain and places its oil under Canadian or British control. An initial suggestion that this would control almost all American oil is immediately corrected because Texas, the Gulf of Mexico, and other domestic sources remain substantial. The narrower conclusion is that Canada would supply a much larger share of the oil the United States otherwise imports. That changes the bilateral energy relationship while leaving the United States with significant domestic production.