Japan has within its sights the obvious but precarious solution for its fiscal mess: a tax hike.

With its debt rising, its population aging and its social security costs set to soar, an increase in the consumption tax allows Japan a chance — perhaps its only chance — to keep pace, perhaps to even cut its current deficit. The International Monetary Fund recommends such a move. So do the country's finance bureaucrats. Polls even suggest that most Japanese citizens understand the need for a raise.

But among Tokyo's top politicians, the tax issue has so far led only to a sluggish form of combat, with disagreements over when rates should jump, how much they should jump and whether they should jump at all.