Reporting from London and Athens— Italy swore in a new Cabinet and Greece’s recently anointed prime minister won an important vote of confidence as both countries scrambled Wednesday to avoid an economic disaster that could torpedo the Eurozone. The two nations are pinning their hopes on unelected, technocratic leaders tasked with bringing down staggering levels of government debt and restoring investor confidence in their badly battered economies. Failure by either country could spell doom for the euro, the currency they share with 15 other European nations. In a solemn ceremony in Rome, former European Union official Mario Monti, a trained economist, took the oath of office as prime…