A second chart showed the benefits of addressing the budget imbalance sooner rather than later. The problem will become twice as hard to solve, in terms of the scale of spending cuts or tax hikes, if America waits until 2025 to take action, compared with actions that begin in 2015.
Already, the CBO report said, the government's official debt to the public is in the process of surging from about 40 percent of gross domestic product (GDP) as the recession began to 62 percent by the end of this year – the highest level as a share of the economy since the period just after World War II.
After issuing the report, Elmendorf presented his views to a fiscal commission created by President Obama, which plans to propose budget solutions later this year. The panel includes Democrats and Republicans, including some who now sit in Congress.
The commission's give-and-take with Elmendorf offered some glimpses of the tough choices and volatile politics that lie ahead.
"As I heard you describe it, what's going to be necessary [is] either a 25 percent increase in taxes or a 20 percent reduction in spending, or some combination thereof," said Sen. Kent Conrad (D) of North Dakota. "Is that correct?"
"That's the order of magnitude, yes," Elmendorf replied.
Such large changes don't need to happen all at once. But if nothing is done, the cost of servicing debt will keep rising as a share of federal spending. With the Greek debt crisis serving as a reminder of what can go wrong, debate has been growing lately about whether the Bush tax cuts should be made permanent for most Americans or partially phased out.