For the last couple of years, the running joke on Wall Street was “Dubai, Mumbai, Shanghai or goodbye.” If you were the C.E.O. of a troubled investment bank desperately looking for cash, you made a pilgrimage to one of those three cities with hat in hand. They were the places most likely to write a quick billion-dollar check; their eagerness should have also been a tip-off. Now you have to wonder about Mumbai and Shanghai, too. Are they next in line to take a fall?

Willem Buiter, a former Bank of England official who was hired as chief economist of Citigroup on Monday, says that Dubai’s credit crisis is just the natural progression of “the massive build-up of sovereign debt as a result of the financial crisis.” He wrote on his blog on The Financial Times’s Web site that the contraction of credit “makes it all but inevitable that the final chapter of the crisis and its aftermath will involve sovereign default, perhaps dressed up as sovereign debt restructuring or even debt deferral.”

With all the money pouring into the region, it would have been hard for any doomsday types to make themselves heard. But there were whispers here and there, pointing out the obvious. David Rubenstein, the co-founder of the private equity giant Carlyle Group who was in Dubai at the conference, remarked to me at the time: “You know, they don’t have any oil here.”

That fact was overlooked by many investors who didn’t want to miss out on a quick buck. What about the risk? The view was, and apparently still is, that if Dubai gets in trouble, its oil-rich neighbors in Abu Dhabi will bail everyone out to avoid damage to their collective reputation and, by extension, the region’s economy. Just as the United States stood behind its banks, in part, to avoid losing the confidence of foreign investors, Abu Dhabi might have to do the same.

That had to be what Citigroup, with its firsthand expertise with bailouts, must have been thinking when it lent $8 billion to Dubai last year. Oh, and here’s an interesting fact: Citigroup made the loan to Dubai on Dec. 14, 2008. Take a look at the calendar  that’s after it received tens of billions in TARP funds. Citigroup’s chairman, Win Bischoff, said at the time, “This is in line with our commitment to the U.A.E. market in general, and reflects our positive outlook on Dubai in particular.” Good call. And what became of all those Shariah-compliant financial instruments that were the hot topic of that panel I attended? It turns out that many of them that were sold prior to the crisis weren’t compliant at all.

The Shariah Committee of the Accounting and Auditing Organization for Islamic Institutions, which is based in Bahrain, ended up changing the rules to make them stricter because of widespread abuse. As Mr. Buiter described them on his blog, “these were window-dressing pseudo-Islamic financial instruments that were mathematically equivalent to conventional debt and mortgage contracts.”

Blessings, alas, can do only so much.