In Moscow, the Kremlin responded to American warnings of economic punishment and isolation for its actions in Crimea with a counterthreat that Moscow might abandon the dollar as a reserve currency and refuse to repay loans to American banks, Reuters reported. The warning came from Sergei Glazyev, a Kremlin aide with limited influence over the formulation of a policy but boasting a reputation for staking out hard-line positions, the news agency said.
http://www.nytimes.com/2014/03/05/world/europe/ukraine.html