David Leonhardt and colleagues at the New York Times present an analysis of US federal debt today that is comprehensive and instructive. They went through several years of Congressional Budget Office reports to try to figure out how the debt has grown to levels not seen since the immediate post-WWII years. Leonhardt writes: The story of today’s deficits starts in January 2001, as President Bill Clinton was leaving office. The Congressional Budget Office estimated then that the government would run an average annual surplus of more than $800 billion a year from 2009 to 2012. Today, the government is expected to run a $1.2 trillion annual deficit in those years. You can think of that roughly $2 trillion swing as coming from four broad categories: the business cycle, President George W. Bush ’s policies, policies from the Bush years that are scheduled to expire but that Mr. Obama has chosen to extend, and new policies proposed by Mr. Obama. The first category — the business cycle — accounts for 37 percent of the $2 trillion swing. It’s a reflection of the fact that both the 2001 recession and the current one reduced tax revenue, required more spending on safety-net programs and changed economists’ assumptions about how much in taxes the government would collect in future years... Read For U.S., a Sea of Perilous Red Ink, Years in the Making here . In addition to the article, you can track the growth of the deficit since 2001 with an interactive graph (see right), and through a much more extensive, helpful chart. Click here to access. You can also read about Leonhardt's methodology here .