(CNSNews.com) – Testifying in the U.S Senate yesterday, Congressional Budget Office Director Keith Hall warned that the publicly held debt of the U.S. government, when measured as a percentage of Gross Domestic Product, is headed toward a level the United States has seen only once in its history—at the end of World War II.To simply keep the debt at the high historical level where it currently sits—74 percent of GDP–would require either significant increases in federal tax revenue or decreases in non-interest federal spending (or a combination of the two).Historically, U.S. government debt as a percentage of GDP hit its...