Here, just south of the Arctic Circle, where the sea ice is vanishing like dew on a July morning, the temperature isn’t the only thing that’s heating up.

Across the region, a warming Arctic is opening up new competition for resources that until recently were out of reach, protected under a thick layer of ice. As glaciers defrost and ice floes diminish, the North is being viewed as a source of not only great wealth but also conflict, diplomats and policy experts say.

In recent months, oil companies have begun lining up for exploration rights to Baffin Bay, a hydrocarbon-rich region on Greenland’s western coast that until recently was too ice-choked for drilling. U.S. and Canadian diplomats have reopened a spat over navigation rights to a sea route through the Canadian Arctic that could cut shipping time and costs for long-haul tankers.

Even ownership of the North Pole has come into dispute, as Russia and Denmark pursue rival claims to the underlying seabed in hopes of locking up access to everything from fisheries to natural gas deposits.

The intense rivalry over Arctic development was highlighted in diplomatic cables released last week by the anti-secrecy Web site Wikileaks. Messages between U.S. diplomats revealed how northern nations, including the United States and Russia, have been maneuvering to ensure access to shipping lanes as well as undersea oil and gas deposits that are estimated to contain up to 25 percent of the world’s untapped reserves.

In the cables, U.S. officials worried that bickering over resources might even lead to an arming of the Arctic.

“While in the Arctic there is peace and stability, however, one cannot exclude that in the future there will be a redistribution of power, up to armed intervention,” a 2009 State Department cable quoted a Russian ambassador as saying.

Concern over competition in the Arctic was partly behind an extraordinary diplomatic gathering last week in Greenland’s tiny capital Nuuk. This year’s meeting of the eight-nation Arctic Council drew seven foreign ministers, including Russia’s Sergey Lavrov and Secretary of State Hillary Rodham Clinton, the highest-ranking U.S. diplomat to attend an Arctic Council session. Accompanying Clinton was a second U.S. Cabinet member, Interior Secretary Ken Salazar.

Clinton and her aides sought to call attention to climate change during the visit, highlighting new studies that show Arctic ice melting far more rapidly than scientists had believed. But Clinton also promoted a message of international cooperation in the Arctic.

“The challenges in the region are not just environmental,” Clinton said in Nuuk following talks with her Danish counterpart, Lene Espersen. “The melting of sea ice, for example, will result in more shipping, fishing and tourism, and the possibility to develop newly accessible oil and gas reserves. We seek to pursue these opportunities in a smart, sustainable way that preserves the Arctic environment and ecosystem.”

Clinton’s presence at the Nuuk meeting was intended to show U.S. support for the Arctic Council as a critical forum for cooperation and to resolve conflicts. With strong backing from the Obama administration, the Council on Thursday approved the first legally binding treaty in its history, a pact that sets the rules for maritime search and rescue in the region. Although modest in scope, the treaty, authored mainly by Russia and the United States, was hailed as a template for future agreements on issues ranging from oil-spill cleanup to territorial disputes.

Significantly, the eight member nations voted to establish a permanent secretariat to the council, to be located in Tronso, Norway. Clinton asserted that the region’s powers must recognize the council as the “preeminent intergovernmental body, where we can solve shared problems and pursue shared opportunities.”

“The opportunities for economic development in the Arctic must be weighed against the need to protect its environment and ecosystems. And governments will not always see eye to eye on how to achieve this balance,” Clinton said. “That’s why this Council is so important.”

In the diplomatic cables obtained by Wikileaks, there was no dispute about rapid warming underway. The predominant questions revolved around how the region’s newly accessible resources would be carved up.

Several cables showed U.S. officials and others seeking to curry favor with Greenlanders and other indigenous groups amid speculation that oil wealth would soon bring independence to the ice-covered island and its 60,000 inhabitants.

One cable authored Nov. 17, 2007, by the U.S. ambassador to Denmark, James P. Cain, detailed how Americans have sought to establish closer links to Greenland’s leaders in an effort to shore up what Cain described as the U.S.’s “real security and growing economic interests in Greenland.”

“A recent study of hydrocarbon potential, led by the U.S. Geological Survey, concluded the continental shelf off northeast Greenland alone could harbor oil and gas reserves to rival Alaska’s North Slope” Cain wrote. “Whether because of man-made climate change or a massive, cyclical shift in weather patterns, Greenland’s carbon riches are more easily accessible now than ever.”

Cain not only proposed establishing a diplomatic post in Greenland, but worked to promote drilling plans that would benefit companies such as Chevron and Exxon-Mobil, part of a four-company consortium that had won oil and gas licenses off the western coast of Greenland.

“To help Greenlanders secure the investments needed for such exploitation, I recently introduced Home Rule Premier [Hans] Enoksen and Minister of Finance and Foreign Affairs Aleqa Hammond to some of our top U.S. financial institutions in New York,” he wrote in the cable.

In some instances the cables reveal American diplomats’ unease with the competition in the Arctic, even among close allies. One missive sent July 31, 2006, from the U.S. Embassy in Ottawa includes the simple summary: “The GOC [Government of Canada] is taking steps to secure sovereign rights over seabed resources that extend to the edge of the continental shelf.”

Kert Davies, research director for Greenpeace USA, said the leaked cables show that when it comes to nations with a claim on the Arctic, “the tensions are higher than we thought.”

“The Arctic Council is woefully unprepared to regulate the corporate interests that strive to get in there,” Davies said, adding that comments like Cain’s show how individual governments will push to provide an advantage to their domestic companies. “When the corporate interests and the government interests align, the government does the corporate interests’ bidding.”

But in an interview, Sweden’s Ambassador to the Arctic Gustaf Lind said there were broad misconceptions about the region. “This is not the unregulated Wild West, but a well-regulated place,” he said.

Eilperin contributed from Washington.