Rubber ice is a rare and stubborn phenomenon that makes sea ice softer, slushier, and more elastic than the dense, hard-packed ice the ship is designed to cut through. The Polar Sea was not just transporting supplies or ensuring operational continuity—it was also facilitating scientific discovery. Perhaps the most notable political adventure for the Polar Sea was in 1994, as the world was entering a new chapter. Despite its historic contributions and the lasting impact of its missions, the Polar Sea reached the end of her service life in 2010. Now the United States faces a new strategic imperative: to ensure that it has the icebreaking fleet necessary to protect national interests in the face of international competition.