Never again.

That is a feeling felt strongest when the pain is fresh. Delay dulls the senses.

It has been three years since the credit crisis began to blossom, and nearly two years since the collapse of Lehman Brothers and the bailout of the American International Group. The lessons of the crisis seemed clear at the time. Financial institutions had taken on far too much leverage. They had too little capital, some of which turned out to be evanescent when it was actually needed. That must never happen again.

That spirit was still with international bank regulators when they met in Basel, Switzerland, last December. Out of that came tough proposed standards. The kinds of things that qualified as capital would be cut back. There would be new requirements...