This article examines the current geopolitical transformation of the Arctic region in response to the interplay of rising great power competition (GPC), the institutional empowerment of Arctic indigenous peoples in domestic and international governing bodies, and the continued polar thaw – issues traditionally discussed separately or in pairs, but not generally all together. It applies classical geopolitical theory to the warming Arctic, finding that the fundamental relationships of Heartland to Rimland, and the isolating buffer of what Mackinder called Lenaland, are in a state of flux, and the once-isolated island chains that dominate the physical geography of the circumpolar Arctic are gaining increasing salience to global security, and must not be overlooked. It examines the political geography of the Arctic and the fundamental importance of its indigenous human terrain, where a future Cold War will either be won or lost.