An opening to the north.

COLUMN: IN OUR OPINION; EDITORIAL FOOTNOTE

The passage of two German merchant ships through Russia's Northern Sea Route - unaided by an icebreaker - offers the most dramatic commercial evidence to date that the Arctic Ocean is donning shades of blue.

Finding ways to navigate the frozen wastes of the North has occupied the imagination of explorers and governments for more than 500 years. The search for a Northwest Passage through the Canadian North often led to tragedy, as in 1845, when Sir John Franklin's expedition went astray and perished from a combination of exposure, disease and starvation. The Northern Sea Route above Siberia has also long been a challenge for cartographers and empire builders.

For most of a century now, advances in navigation and technology have enabled humans to venture into the Arctic with fair assurance of a safe return, but it is only in the last several years that the recession of Arctic sea ice has made navigation without the help of icebreaking ships a reality. The passage of the ships Fraternity and Foresight from South Korea, through the Bering Strait, and then westward along the usually daunting coast of Siberia, means a savings of nearly 3,500 miles over the usual route through the Pacific and Indian oceans, Suez Canal, and familiar waters of the Mediterranean.

Their passage means more, however, than delivering construction materials more cheaply than before. It emphasizes that a new age of commercial enterprise is opening, one that involves important and difficult questions of navigation rights, territorial claims, and environmental impacts. It's time to break out the maps, hammer out the rules, and ensure that the new passages in the north lead to cooperation rather than conflict.