In addition to lobbying, big financial players have another potential weapon in their battle against safety and soundness. This one is more hidden from view and comes from, of all places, the World Trade Organization in Geneva.

Back in the 1990s, when many in Washington — and virtually everyone on Wall Street — embraced the deregulation that helped lead to the recent crisis, a vast majority of W.T.O. nations made varying commitments to what’s called the financial services agreement, which loosens rules governing banks and other such institutions.