As a default would demand a change in the currency involved in private contracts, business partners from other EU countries would surely sue, legal uncertainties would drag on and on, and an exiting country’s trade with its main trading partners would be impaired for years to come. So none of the countries at risk would seriously consider reintroducing a national currency.
但是希腊，葡萄牙，意大利和爱尔兰不是阿根廷。欧盟条约不允许退出欧洲货币联盟。如果违约方要求改变私人契约中涉及的货币，来自欧盟其他国家的商业伙伴肯定会提起诉讼，法律上的不确定性会拖拉个没完没了，退出国与主要贸易伙伴之间的贸易会在未来好些年里遭到破坏。所以身处危险的国家都不会认真考虑重新引进本国货币。