Forexsq.com - In an interview with SPIEGEL, Harvard economist Kenneth Rogoff, 58, says it was a mistake to bring all the southern European countries into the common currency. He also argues that Greece should be granted a "sabbatical" from the euro and that a United States of Europe may take shape far sooner than many believe. SPIEGEL: Mr. Rogoff, the eurozone finance ministers are likely to soon provide Greece with new loans totalling €130 billion ($171 billion), with the aim of stabilizing the country for the next few years. Will that save the euro? Rogoff: It is hardly the final word, even for Greece