Sept. 18, 2007 — -- The reports from the world's scientists depict the Arctic sea ice cap now shrunk to its smallest size in history — the great melting uncovering vast stretches of the Arctic Ocean and opening up a northwest shipping lane mariners have been dreaming about since Christopher Columbus discovered America.
The reports from the world's diplomats and military planners say there's a new theater of war — at least cold war — where tensions are heating up because the world is.
Watch a video of Bill Blakemore's tour of the ice wonders of Greenland here.
In the Arctic these days, there are Danish commando dog-sled patrols guarding northern Greenland.
While U.S. icebreakers are mapping the seabed, Russian subs are planting their flag on the same seabed.
And the Canadian navy is expanding its Arctic patrols, running new military exercises, ordering six new military patrol ships, while the Canadian government is building up two Arctic military bases.
"As there was in the American West in the 1800s, there's a great land grab going on, but most of the land is at the bottom of the seafloor," Brookings Institution scholar William Antholis said.
Under that seafloor lie giant, but largely unexplored, oil and gas fields. Over it are new, warm-water fisheries, all now accessible as ice melts away.
The melting has also left the fabled Northwest Passage — providing a whole new way for ships to travel between the Pacific and Atlantic oceans — fully open for the first time.
As the Northwest Passage melts open, an entire stretch of the western coast of Greenland becomes strategically much more important as the eastern entrance to the passage from Europe and the eastern United States.
Denmark, which governs Greenland, is watching warily as the world's commercial and military fleets get ready to use the Northwest Passage in coming years as the accelerating warming keeps it open longer each summer.
And prospecting mineral companies have been looking at the possibility of new reserves of nickel and even diamonds along the northern coast of Greenland now becoming more accessible as sea ice shrinks away.
The Russians have long claimed nearly half of the Arctic Ocean is theirs.
There's a story, possibly apocryphal, that Joseph Stalin once drew his finger across a map across the Arctic Ocean from the tip of Finland to Alaska's Bering Strait — right through the North Pole — saying "This half is ours."
Meanwhile, Canada claims that most of the Northwest Passage routes, which pass between many Canadian islands across the top of the country, are inside its territorial waters.
"But you can't just say, 'They're Canadian,' and sit back," David Biette, director of the Canada Institute at the Woodrow Wilson Center at Princeton, told ABC News. "You have to assert that sovereignty, and a way to assert it is to put up a military training base, and having some ships to patrol the area to say they are Canadian."
For its part, the United States — like Russia and Denmark and many other countries — believes the Northwest Passage must be shared.
"We believe it's an international waterway," President Bush said earlier this year with the Canadian prime minister standing by his side after discussion in which they had agreed to continue to disagree over the newly opening seaway.
The United States argues that, though the Canadian Islands are indeed very close to the narrow Northwest Passage, it should be agreed that it's an international seaway, similar to the internationally agreed open sea lanes, for example in the narrow straits of Molucca.
Overall, no one knows exactly how much mineral wealth, strategic advantage and even new warm-water fisheries profit may be produced by the great warming, but nations are jockeying for position to deal with it and take advantage of it.
"I would be surprised if this ended up leading to a shooting war," said Bookings' Antholis. "That said, these are the kinds of tensions that take up leaders' time and leaders often don't want to be bothered with."
In centuries past, such disputes might have meant war.
That may not seem likely now, but as global warming keeps opening these waters, it's producing new tensions among old friends.