As the United States, Russia and China race to turn a melting Arctic into the world’s next major economic gateway, their strategic ambitions face a hidden threat: thawing permafrost. Since returning to office last year, US President Donald Trump has pushed to expand America’s Arctic footprint. This includes investing in icebreakers to counter Russian and Chinese shipping ambitions, unlocking natural resources in Alaska and renewing efforts to buy or annex Greenland. Yet, as the three powers vie...