In the years between the World Wars, the rapidly-industrializing Soviet Union (or U.S.S.R.) planned to rebuild the navy, but the Great Purge prevented any meaningful progress and the Red Fleet would only have a handful of cruisers, obsolete battleships and a reasonable number of destroyers when the U.S.S.R. entered World War II in June 1942 with Operation Barbarossa (Germany's invasion of the Soviet Union). However, the Soviet Navy would go on to perform with distinction: their large number of submarines were used to great effect by the Baltic Fleet against the Kriegsmarine and the Finnish Navy despite suffering great losses themselves; the Soviet Naval Aviation service, while not having a single aircraft carrier, sank more ships and crew than any other unit of the Soviet Navy; and Russian resourcefulness and tenacity was exemplified by naval guns still being put to use even after extensive damage to individual ships (such as battleship Marat).