America’s financial situation is unsustainable. In 2009 the federal government spent $3.5 trillion but collected only $2.1 trillion in revenue. The result was a $1.4 trillion deficit, up from $458 billion in 2008. That’s 10 percent of gross domestic product, a level unseen since World War II. Worse, the Congressional Budget Office (CBO) projects that we’ll be drowning in red ink for the foreseeable future, with annual deficits averaging $1 trillion during the next decade. While these figures are dramatic, they pale in comparison to what the federal government owes foreign and domestic investors. According to the CBO, in 2009...