For centuries, Europeans sought the elusive Northwest Passage that would link Europe to the Far East and China. Early visitors to Canada's northern coasts included Viking sailors and Basque whalers. Then came the prominent explorers -- John Cabot, Vasco da Gama, Martin Frobisher and Sir John Franklin. Now that global warming threatens to melt much of the Arctic ice cap, conflict over the Northwest Passage and the resource riches of the Arctic is intensifying.