Euro Zone Needs to Become United States of Europe: O'Neill

5:00 AM ET Wed, 23 May 2012

Jim O'Neill, chairman of Goldman Sachs Asset Management, told CNBC, "Once one country exits the euro zone it breaks the notion of it being a true currency union and some king of hard currency peg, so that is a big moment and they will have to respond very clearly and critically to not only ring fence the others but make is clear that no one else is going to leave."