A gripping blend of travelogue and frontline reporting that reveals how climate change, military ambition, and economic opportunity are transforming the Arctic into the epicenter of a new cold war, where a struggle for dominance between the planet's great powers heralds the next global conflict. Russian spies. Nuclear submarines. Sabotaged pipelines. Undersea communications severed in the dark of night. The fastest-warming place on earth--where apartment buildings, hospitals, and homes crumble daily as permafrost melts and villages get washed away by rising seas--the Arctic stands at the crossroads of geopolitical ambition and environmental catastrophe. As climate change thaws the northern latitudes, opening once ice-bound shipping lanes and access to natural resources, the world's military powers are rushing to stake their claims in this increasingly strategic region. We've entered a new cold war--and every day it grows hotter. In Polar War, Kenneth R. Rosen takes readers on an extraordinary journey across the changing face of the far north. Through intimate portraits of scientists, soldiers, and Indigenous community leaders representing the interests of twenty-one countries across four continents, he witnesses firsthand how rising temperatures and growing tensions are reshaping life above and below the Arctic Circle. He finds himself on the trail of Navy SEALs training for arctic warfare, embarks on Coast Guard patrols monitoring Russian incursions, participates in close-quarter-combat training aboard foreign icebreakers in the Arctic sea ice, and visits remote research stations where international cooperation is giving way to espionage and the search for long-frozen biological weapons. Drawing on hundreds of interviews and three years of reporting from the frontlines of climate change and great power competition, Rosen blends incisive analysis with the vivid immediacy of a travelogue. His deeply researched and personal accounts capture the diverse landscapes, people, and conflicted interests that define this complex northern region. The result is both an elegy for a vanishing landscape and an urgent warning about how the race for Arctic dominance could spark the next global conflict.