While many questions concerning Oil-for-Food remain unanswered, one conclusion has become abundantly clear: Kofi Annan should resign. The decision to call for his resignation does not come easily, but I have arrived at this conclusion because the most extensive fraud in the history of the U.N. occurred on his watch. In addition, and perhaps more importantly, as long as Mr. Annan remains in charge, the world will never be able to learn the full extent of the bribes, kickbacks and under-the-table payments that took place under the U.N.'s collective nose.

Mr. Annan was at the helm of the U.N. for all but a few days of the Oil-for-Food program, and he must, therefore, be held accountable for the U.N.'s utter failure to detect or stop Saddam's abuses. The consequences of the U.N.'s ineptitude cannot be overstated: Saddam was empowered to withstand the sanctions regime, remain in power, and even rebuild his military. Needless to say, he made the Iraqi people suffer even more by importing substandard food and medicine under the Oil-for-Food program and pawning it off as first-rate humanitarian aid.

Since it was never likely that the U.N. Security Council, some of whose permanent members were awash in Saddam's favors, would ever call for Saddam's removal, the U.S. and its coalition partners were forced to put troops in harm's way to oust him by force. Today, money swindled from Oil-for-Food may be funding the insurgency against coalition troops in Iraq and other terrorist activities against U.S. interests. Simply put, the troops would probably not have been placed in such danger if the U.N. had done its job in administering sanctions and Oil-for-Food.

This systemic failure of the U.N. and Oil-for-Food is exacerbated by evidence that at least one senior U.N. official -- Benon Sevan, Mr. Annan's hand-picked director of the U.N.'s Oil-for-Food oversight agency -- reportedly received bribes from Saddam. According to documents from the Iraqi oil ministry that were obtained by us, Mr. Sevan received several allotments of oil under Oil-for-Food, each of which was worth hundreds of thousands, if not millions, of dollars.

To make matters worse, the actions of Mr. Annan's own son have been called into question. Specifically, the U.N. recently admitted that Kojo Annan received more money than previously disclosed from a Swiss company named Cotecna, which was hired by the U.N. to monitor Iraq's imports under Oil-for-Food. Recently, there are growing, albeit unproven, allegations that Kofi Annan himself not only understands his son's role in this scandal -- but that he has been less than forthcoming in what he knew, and when he knew it.

The final losers are the U.N. and Kofi Annan. The U.N. has been invisible. As Kofi Annan has been trying to keep his head above oil, he has issued his usual appeal for restraint. But this crisis has brought forth the heroes of the Cold War from retirement -- Vaclav Havel, Lech Walesa and Margaret Thatcher -- to encourage the orange revolutionaries. And Annan cannot begin to compete with their moral authority or the legitimacy they can bestow.