No one argues that the staggering deficits run up by the American government in a bid to rescue the economy are desirable, healthy or even sustainable — not if the national debt continues to swell at its current pace. But considerable debate centers on when and how vigorously to start easing off Washington’s borrowing habit, with substantial risks at both extremes.

Pull back on government spending now, the argument runs, and condemn an already hobbled American economy to years of mass joblessness and anguish. Indeed, some economists are already arguing that with unemployment near double digits, the government must consider giving another dose of stimulus spending now, despite the fact that this will add to the deficit.

Keep spending...