Crimea's Moscow-backed leaders declared a 96% vote in favour of quitting Ukraine and annexation by Russia in a referendum Western powers said was illegal and will bring immediate sanctions. As state media in Russia carried a startling reminder of its power to turn the United States to "radioactive ash", US President Barack Obama spoke to Vladimir Putin, telling the Russian president that he and his European allies were ready to impose "additional costs" on Moscow for violating Ukraine's territory. The...