Historical and cultural claims are not worth much when it comes to sovereignty over territory; if they were then every country in the world would be involved in disputes with their neighbours. In 1994 Russia agreed the Budapest Memorandum with the US, UK and Ukraine in it committing “to respect the independence and sovereignty and the existing borders of Ukraine [and] reaffirm their obligation to refrain from the threat or use of force against the territorial integrity or political independence of Ukraine”. [1] Russia signed agreements in 1997 that recognised Crimea as a part of Ukraine in return for a lease on the base of the Russian Black Sea Fleet. [2] Russia has therefore not been contesting sovereignty and so has no legal claim.  [1] Presidents of Ukraine, Russian Federation and United States of America, and the Prime Minister of the United Kingdom, ‘Budapest Memorandums on Security Assurances, 1994’, cfr.org, 5 December 1994  [2] Felgenhauer, T., ‘Ukraine, Russia, and the Black Sea Fleet Accords’, dtic.mil, 1999