No country has ever left the joint currency, which launched in 1999, and there is no mechanism in place for one to do so. If the talks had failed, Greece could have faced bankruptcy and a possible exit from the euro, the European single currency that the country has been a part of since 2002. The eal could pave the way for the European Central Bank to extend emergency liquidity assistance to Greek banks. Without it, they risk running out of cash this week.