The decommissioning of Russian nuclear-powered vessels is an issue of major concern to the United States and to Scandinavian countries near Russia. From 1950 to 2003, the Soviet Union and its major successor state, Russia, constructed the largest nuclear-powered navy in the world, with more ships than all other navies combined: 248 submarines (91 attack submarines, 62 cruise missile submarines, 91 ballistic missile submarines and four research submarines), four Kirov-class battlecruisers, and a missile test ship, as well as nine icebreakers. Many were or are powered by two reactors each, bringing the total to 468 reactors.