Peace.

“If there weren’t almost insurmountable technical and financial challenges to get that stuff, why isn’t it happening?” Chandler said.

Russia also has problems on land, where ice roads needed for development in the Western Siberian basin are melting earlier, leaving less time for exploration and development, Chandler said.

U.S. Navy Cmdr. Andrew Garlington, who works on maritime security policy, said the Navy is planning for increased use of the Arctic.

“But let me give you a caution,” Garlington said. “When you hear ice-free waters in the Arctic, that doesn’t mean it’s free of all ice. That just means it’s less than 10 percent coverage. It’s still a very dangerous and dynamic environment up there.”

The Coast Guard also is looking north and working with Canada and Russia on oil spill response plans.

The Northwest Passage between Baffin Bay and the Beaufort Sea was navigable for a period starting late last August, and also the year before. But Michael Storgaard, a spokesman for A.P. Moller-Maersk, the world’s biggest shipping company, said it’s shallow with many narrow straits, not fully mapped in detail and lacking large-scale rescue and repair facilities.

“For now, we do not see any immediate commercial possibilities in connection with the Northwest Passage,” he said. “Our view is also that it will be some time, perhaps even decades, before we see a more consistent commercial utilization.”