Yesterday, a submersible lowered a titanium Russian flag onto the Arctic seabed, near the North Pole, at a depth of almost 14,000 feet. Canada immediately mocked Moscow’s stunt. “This isn’t the 15th century,” said Ottawa’s Minister of Foreign Affairs, Peter MacKay. “You can’t go around the world and just plant flags and say ‘We’re claiming this territory.’ ”

International law permits Russia, Canada, the United States, Denmark, and Norway, the nations with coastlines inside the Arctic Circle, to enforce 200-mile exclusive economic zones north of their shores. The Kremlin, however, claims a bigger zone that includes the seabed under the North Pole. It maintains that the Lomonosov Ridge, which runs under the Pole, forms part of Siberia’s continental shelf. Canada and Denmark maintain competing claims to the same ridge. (Why do so many nations want the Ridge? Because a receding polar cap may someday make drilling for hydrocarbons there feasible.)

Russia is not the only nation to make outsized claims on continental shelves. China, for instance, believes it has rights to a good portion of Japan’s coastline. China also maintains claims on the continental shelves of the Philippines, Brunei, Indonesia, Malaysia, and Vietnam (as well as the entire South China Sea).

The United States is party to few economic-zone disputes. Nonetheless, it is the final guarantor of the international system. As such, it should be taking a greater interest in making sure that claims are settled peacefully—and that the rights of free passage are protected—whether or not the Senate sees fit to ratify the controversial Law of the Sea Convention, as the Bush administration wants it to do. And the first item on our agenda should be to talk openly and pointedly to Beijing and Moscow about their grand claims and methods of bolstering them.