Both countries want to stake their claim to the territorial waters that would follow discovery of continental shelf that is geologically similar to their mainland. A lot is at stake -– including an estimated 90 billion barrels of oil, according to the US Geological Survey, or a fifth of the world’s undiscovered exploitable reserves. A summit in May about how to divide the reserves broke down without reaching agreement.

Claims must be filed to Arctic resources by 2009, according to the UN Convention on the Law of the Sea (UNCLOS), while supporting information must be submitted to the United Nations by the end of 2013 -– the year that researchers from the US Naval Postgraduate School at Monterey, California predicts could see an entirely ice-free Arctic in summer. A previous mission run by Canada and Denmark had found that the Lomonosov ridge under the Arctic is part of the North American and Greenland continental plates, challenging Russian claims of ownership (the country very publicly sent a submarine to plant a flag on the ridge last summer).

The explosion of interest is readily explicable: Nearly 20 square kilometres of the Ward Hunt Ice Shelf broke off the coast of Ellesmere Island in the Canadian Arctic in July, and the US National Snow and Ice Data Center announced at the end of August that Arctic sea ice has shrunk to the second-smallest extent since satellite records began. This allows for a faster pace of oil and gas exploration in the region than was expected, since over 80% of the drilling must be offshore. It will also allow easier navigation of the area by normal ships, including fishing and transport vessels -- and surface warships.

A leaked report prepared by the Canadian military last year found the country unprepared to defend its far north, despite Arctic operations having become a strategic priority for Canadian forces. Meanwhile the commander of Russian military training, Lieutenant-General Vladimir Shamanov, announced in June that some of his country’s units were being trained to conduct combat operations in the Arctic. If fights over Arctic sovereignty cannot be resolved diplomatically, military tensions could increase, in an increasingly crowded Arctic zone.