European leaders denounced Russia's attempt to "blackmail" Ukraine's allies over gas supplies, as Western sanctions batter the Russian economy already struggling with its worst crisis since the 1991 fall of the Soviet Union. Ukraine said Europe should stop depending on Russia for trade after it halted gas supplies to Bulgaria and Poland for not paying in roubles, as the shutoff exposed the continent's weaknesses and divisions on Wednesday. Germany, the biggest buyer of Russian energy, hopes to stop importing Russian oil within days, but warned a Russian energy embargo or blockade would tip Europe's largest economy ... (full story)