– War on the Rocks – From the 1950s until today, Russia’s dangerous Atlantic submarine force has represented the technological pacing threat for the U.S. Navy in the undersea domain. However, this trend is slowly changing. It will be the waters of the Pacific, not the Atlantic, where the U.S. Navy will be most sorely tested. In his 2016 posture hearing, Commander of U.S. Pacific Command Admiral Harry Harris noted that Chinese, Russian, and North Korean submarines constitute 150 of 200 submarines currently in the Pacific. Numbers only tell part of an increasingly ominous story. The trajectory of submarine investments made by these nations — and ten other Asia-Pacific countries — will create a far more dangerous undersea domain in the Asia-Pacific by 2030. Developing the policies and frameworks that will enable effective shaping of this environment must be started before the crisis hits.