"In fact, all five nations with Arctic borders ? Canada, Denmark, Norway, Russia, and the US ? have engaged in at least some saber rattling over the frozen territory. And it wouldn't be happening without global warming. Roughly 386,000 square miles of Arctic ice melted in 2007 alone, opening the fabled Northwest Passage for the first time in recorded history. The melt also made the billions of barrels of oil thought to be under the Arctic suddenly seem within our grasp. Some are calling it the Cold Rush."