JUST a quarter-century ago, and for millenniums before that, the Arctic Ocean was covered year-round by ice, creating an impregnable wilderness that humans rarely negotiated. Today, as the effects of global warming are amplified in the high north, most of the ocean is open water during the summer and covered by ice only in the winter.

This unexpected transformation has radically altered the stakes for the Arctic, especially for the eight nations and indigenous peoples that surround it. But while there has been cooperation on extracting the region’s oil, gas and mineral deposits, and exploiting its fisheries, there has been little effort to develop legal mechanisms to prevent or adjudicate conflict. The potential for such conflict is high, even though tensions are now low.

Several countries, along with corporations like ExxonMobil and Royal Dutch Shell, are preparing to exploit the region’s enormous oil and natural gas reserves. New shipping routes will compete with the Panama and Suez Canals. Vast fisheries are being opened to commercial harvesting, without regulation. Coastal areas that are home to indigenous communities are eroding into the sea. China and the European Union are among non-Arctic governments rushing to assert their interests in the region. Some states have increased military personnel and equipment there.

The most fundamental challenge for the Arctic states is to promote cooperation and prevent conflict. Both are essential, but a forum for achieving those goals does not yet exist.