The recession is ending but the debt pile only grows: The U.S. is now more than $12 trillion in the red. Servicing that national debt will cost the country $202 billion this year, and more than $700 billion per year by 2019, according to White House estimates. For comparative purposes, $500 billion in interest expenses could cover the federal budgets this year for education, energy, homeland security, the wars in Iraq and Afghanistan, and still have some left over. While this year's spending surge is widely believed to be a necessary response to the financial crisis and recession, the long-term budget crisis, which arrived just as baby boomers are beginning to retire en masse, has sent the Treasury is scrambling to lock in today's low interest rates by shifting short-term borrowings to long-term bonds. But much like overstretched homeowners with a subprime mortgage, the government can probably look forward to payment shock.