The recent news about Japan's economy has been increasingly positive. The same, alas, cannot be said of its top economic managers. Just when the government and the Bank of Japan should be working together closely to nurse the nascent recovery, they are being drawn into needless quarrels that threaten to snuff it out.

Their differences burst into the open last weekend when Hidenao Nakagawa, the ruling Liberal Democratic Party's policy chief, publicly questioned the BoJ's right to run its own policy and threatened action to curb its statutory independence. Hasty efforts by the ministry of finance to paper over the dispute have failed to quell the tensions underlying it.