AP Photo

In 2009, downgrades and debt auction failures in countries like the UK, Greece, Ireland and Spain were a stark reminder that unless advanced economies begin to put their fiscal houses in order, investors and rating agencies will likely turn from friends to foes. The severe recession, combined with a financial crisis during 2008-09, worsened the fiscal positions of developed countries due to stimulus spending, lower tax revenues and support to the financial sector. The impact was greater in countries that had a history of structural fiscal problems, maintained loose fiscal policies and ignored fiscal reforms during the boom years. Going forward, a weak economic recovery and an aging population is likely to increase the debt burden of many advanced economies, including the U.S., Britain,...