And a consistent global preference for the U.S. dollar over all other currencies gives the country unique external liquidity.

WHITEHOUSE: Press Briefing

In these circumstances, propping up banks is also helping to prop up countries, because the ECB is directly or indirectly providing external liquidity to national financial institutions that the markets are no longer willing to provide.

BBC: Draghi's message for artful euro-dodgers

However, most global trade, Asia's external debt, foreign-exchange liquidity and financial assets are still denominated in dollars.

ECONOMIST: The dollar's dive

"The authorities' programme is intended to support Ukraine's return to economic and financial stability, by addressing financial sector liquidity and solvency problems, by smoothing the adjustment to large external shocks and by reducing inflation, " said Mr Strauss-Kahn.

BBC: IMF aid for Ukraine and Hungary