Russian troops block the Ukrainian marine battalion in the Crimean city of Feodosia on March 23, 2014. Elite Russian troops firing into the air and backed by armoured vehicles stormed a Ukrainian airbase in Crimea on Saturday as Russia's defiant march across the rebel peninsula rolled on despite sanctions and growing global isolation.AFP PHOTO/ DMITRY SEREBRYAKOV        (Photo credit should read DMITRY SEREBRYAKOV/AFP via Getty Images)