It's bad enough that Greece's debt problems have rattled global financial markets. In the world's largest economic and military power, there's a far more serious debt dilemma.
For the U.S., the crushing weight of its debt threatens to overwhelm everything the federal government does, even in the short-term, best-case financial scenario -- a full recovery and a return to prerecession employment levels.
The government already has made so many promises to so many expanding "mandatory" programs. Just keeping these commitments, without major changes in taxing and spending, will lead to deficits that cannot be sustained.
Take Social Security, Medicare and other benefits. Add in interest payments on a national debt that now exceeds $12.3 trillion. It all will gobble up 80 percent of all federal revenues by 2020, government economists project.
That doesn't leave room for much else. What's left is the entire rest of the government, including military and homeland security spending, which has been protected and nurtured by the White House and Congress, regardless of the party in power.
The U.S. debt crisis also raises the question of how long the world's leading power can remain its largest borrower.
Moody's Investors Service recently warned that Washington's credit rating could be in jeopardy if the nation's finances didn't improve.
Despite election-year political pressure from voters for lawmakers to restrain spending, some recent votes suggests that Congress, left to its own devices, probably isn't up to the task of trimming deficits.