Two years ago, Moscow brought its own war games across the Bering Sea, with Russian commanders testing weapons and demanding that American fishing boats operating in American fishing waters steer clear – an order which the US Coast Guard has advised them to observe. Russia has repeatedly sent military planes close to US airspace, leading US planes to rush to intercept and warn them.

This month, in response to escalating international sanctions against Russia, a Russian member of parliament demanded that Alaska, purchased by the United States from Russia in 1867, be returned to Russian control – a move perhaps rhetorical that nonetheless reflected the deteriorating relationship between the two world powers.

For centuries, the vast waters of the Arctic offshore have been largely ice-encased no-man’s land whose exact territorial boundaries – claimed by the United States, Russia, Canada, Norway, Denmark and Iceland – remained uncertain. But as melting sea ice opened up new shipping lanes and nations watched the vast reserves of hydrocarbons and minerals beneath the Arctic ocean floor, the complex treaties, claims and border areas that govern the region have been opened to further disputes.

Canada and the United States have never agreed on the status of the Northwest Passage between the North Atlantic and the Beaufort Sea. China, too, has struggled to establish itself, declaring itself a “state near the Arctic” and partnership with Russia promote “sustainable” development and increased use of Arctic trade routes.

Russia has made it clear that it intends to control the so-called Northern Sea Route off its northern coast, a route that dramatically shortens the sailing distance between China and northern Europe. US officials have complained that Russia is illegally demanding other nations seek permission to pass and threatening to use military force to sink vessels that do not comply.

“We’re stuck in a pretty tense situation there,” said Troy Bouffard, director of the Center of Arctic Security and Resilience at the University of Alaska Fairbanks. “Either we acquiesce to Russia, its extreme control of surface waters, or we elevate or compound the problem.”