The Bering Strait is an 82-kilometer-wide maritime passage connecting the Pacific Ocean with the Arctic Ocean, separating the Chukchi Peninsula at the eastern tip of Russia from the Seward Peninsula in Alaska, United States. The Diomede Islands divide the strait into two: Russian Big Diomede and American Little Diomede, separated by just 3.8 kilometers and by the International Date Line, while the strait has an average depth of only 30–50 meters. It is a critical migration route for gray whales and walruses, a passage for nutrient-rich Pacific waters into the Chukchi Sea ecosystem, and a proposed location for a railway tunnel or bridge connecting Asia and America. In this Risk, the two Diomede Islands are strategic island territories controlling the passage between continents, Chukotka is the Asian gateway to the Arctic, Alaska is the American gateway, and whoever controls the strait can cut off or facilitate maritime traffic between the Pacific and Arctic.