'You don't have to predict it. We're in it." Thus did Paul Volcker respond to a question Tuesday about whether he still predicted a "dollar crisis" in the coming years. We hope current Federal Reserve Chairman Ben Bernanke is paying attention.

Mr. Volcker, a former Fed chief, has a well-earned reputation for straight talk, but there is always strong institutional pressure not to second-guess one's successors at a place like the Federal Reserve. This makes his speech to the Economic Club of New York all the more remarkable...