In putting a floor under the world's third-largest economy, Japan is going for broke. Minus the broke part.

The central bank has effectively pledged to do almost anything to contain the cost of borrowing, even entertaining proposals that challenge its independence. The rest of the world, including the U.S. Federal Reserve, is watching with great interest. Far from being a policy outcast, Japan may be writing the future.

Tokyo's stimulus barrage this week was replete with superlatives suited to the gravity of the coronavirus pandemic. Prime Minister Shinzo Abe unveiled his second package in two months worth about ¥117 trillion, each installment dwarfing the response to the Great Recession. The extra budget required to fund this fiscal expansion will be a record ¥31.9 trillion. Tokyo's debt load, already the greatest among major economies, will climb.