Ships, shipbuilding and access to the sea define Russia and the influence it can exert. Since the 17th century, Russia’s shipyard industry has been in a perpetual state of flux as the country seeks access to water outlets through military conquest. The country's ability to secure and modernize warm water ports has been regularly disrupted by domestic and international conflict, often resulting in the destruction and degradation of the shipyard industry as a whole. The need to make war to protect its naval power has led Russia to prioritize its military shipyard industry above civil shipbuilding. This was certainly the case in the Russian annexation of Crimea and in the support of the Donbas separatist movements to retain control of the port of Sevastopol, which forced Ukraine to cut off export of important components and shipyard services to Russia critical to its naval modernization program.