What's the balance sheet of the U.S. government like, and is it vulnerable?
As of April 2008, U.S. federal, or government, debt was around $9.5 trillion ($9,500,000,000,000).
Tax revenue is about $2.5 trillion, but government spending is about $3 trillion. This means the debt is growing by around $0.5 trillion every year.
Interest payments alone cost the government around $0.5 trillion per year.
On a per-resident basis, this means: Tax income of $8,200; spend of $9,800; a loss of $1,600; cumulative debt of $31,000.
This represents debt of 3.8 times income, and a deficit of 20% of income.
On a personal level, in the U.S. and UK, this has become relatively common. But it has also caused a recent collapse in the debt market.
On a public level, the U.S. government may suffer an equivalent collapse. For the moment, though, we are all looking the other way.