Canada's unresolved Arctic boundary disputes with the United States could be heating up with a new American push to join the international treaty on the Law of the Sea, say experts on both sides of the border.
Drawn by resource wealth and climate change concerns, the Bush administration is asking the U.S. Senate to approve the treaty and give the U.S. legal tools to press its claims to an energy-rich wedge of the Beaufort Sea that Canada considers its own.
"That tells me we're probably going to be winding up in a dispute," said Rob Huebert of the Centre for Military and Strategic Studies at the University of Calgary.
"Once they've ratified, they can get serious about determination of their continental shelf."
The Law of the Sea treaty came into effect in 1994 and has now been ratified by 152 countries as well as the European Union. The U.S. has voluntarily complied with its provisions but has never signed it.
But last week, President George W. Bush issued a release supporting the treaty and urging the Senate to approve it.
"(The treaty) will secure U.S. sovereign rights over extensive marine areas, including the valuable natural resources they contain," Bush said.
One of the areas Bush likely has in mind is the water along the border between Alaska and the Yukon.
Canada has long insisted the international border continues through the ocean in a straight line from the land. The U.S. argues instead that the border angles 30 degrees to the east.
The area is considered to have high oil and gas potential. Alaska has put exploration rights to the block up for sale several times, but no company has bid on it while its nationality remains disputed.
The Law of the Sea treaty allows signatories to establish jurisdiction over offshore resources based on how far their continental shelf extends under the sea. Signing on to the treaty would set the rules for negotiating the location of the border, said Huebert.
"It's all about getting in line for when the inevitable division of the Arctic comes into play. The Americans know we're serious about the determination of our continental shelf."
Arctic waters are behind the administration's push to ratify the treaty, said U.S. Rear Admiral (Ret.) Richard West, now president of the Consortium for Oceanographic Research and Education.
"Most of our interest is in and around Alaska," said West.
General concern for the Arctic in light of the effects of climate change is also behind the new interest in the treaty, West said.
"It's absolutely essential we accede to it so we can sit down and negotiate with our partner Canada. You can't participate in the negotiations until you become part of the treaty."
A 2004 document prepared for the state of Alaska suggests economic interests are also important.
"Ratification of the treaty could, therefore, allow the United States to make a claim to an area of submarine terrain covering nearly half again the size of the state of Alaska," said the Sea Change report. "This continental ridge is known to be rich in oil, natural gas and methane hydrates."
Canada, the U.S., and other Arctic countries such as Denmark and Russia are all busily engaged in mapping the outer edges of their continental shelves in preparation for making their offshore claims.
"One of the real beauties of (the treaty) is that it sets out scientific rules and principles on how to set the boundaries out," said Richard MacDougall, a hydrographer with the Bedford Institute of Oceanography in Dartmouth, Nova Scotia.
Still, tough talks likely lie ahead for the Yukon and Alaska.
"In most cases, those lateral boundaries become negotiations," said MacDougall.
Although attempts to ratify the Law of the Sea date back to the Reagan administration, West says the treaty has enough influential backing in the Senate to likely make it to a vote.
"I think it's the best chance we've ever had," he said. "I think there's a good chance it will pass this Congress."