The harsh, sparsely populated Arctic is warming and sea ice is falling, which means governments are looking north for both economic ventures and as an arena...

The harsh, sparsely populated Arctic is warming and sea ice is falling, which means governments are looking north for both economic ventures and as an arena of strategic competition.

This goes even more so for the Kremlin. Russia has the longest Arctic border in the world, and its oil and gas economy depends on Arctic drilling. Russia has built dozens of icebreakers — even nuclear-powered icebreakers — to help clear passages for ships heading to and from Europe and the Pacific.

The U.S. icebreaker fleet is only a fraction of that size.

Russia is also building up its Arctic military forces. It’s adapting surface-to-air missiles for use in temperatures below -58 degrees Fahrenheit, designing resupply ships with reinforced hulls — necessary when around floating ice — and moving troops and warplanes to the north.

Will Russia intrude on the Arctic territories of other nations, or does the build-up reflect fear on the Kremlin’s part? What will the United States do in response? And what would an Arctic war look like?