ROLF EKEUS, a Swedish diplomat, once personified the most sustained effort ever undertaken to deprive a country of weapons of mass destruction (WMD). He was the leading figure in a programme to enforce peace terms on Saddam Hussein, Iraq’s dictator, in 1991, forcing him to renounce nuclear, biological and chemical weapons and long-range rockets.

His United Nations Special Commission (UNSCOM) had powers to inspect any building, to confiscate documents and to seize and destroy weapons and equipment. Its monitors scored an early success by grabbing documents pertaining to Iraq’s nuclear ambitions. And it forced Saddam to admit dabbling with germ warfare and to stop. By 1998, when UNSCOM was stood down, it had exposed Saddam’s efforts to develop all manner of deadly weapons and missiles, and largely put a stop to them.

So Mr Ekeus had a told-you-so feeling when the Americans, after invading Iraq in 2003, found no weapons of mass destruction (WMD). “I would have been surprised if any deadly weapons had been found,” he says. But his effort may represent a unique moment in history. The UN Security Council invested him with extraordinary authority because, for different reasons, all five permanent members wanted him to succeed.

At least in the immediate aftermath of the 1991 victory, the American administration wanted Iraq, without WMD but otherwise flourishing, as a responsible power in the Middle East and counterweight to Iran. Russia wanted Iraq to get back on its feet and settle its debts for Soviet arms deliveries. France saw Iraq as a promising arena for oil deals.

The International Atomic Energy Agency laboured to monitor Iraq’s nuclear-fuel cycle, but for other possible misbehaviour, including efforts to make poison gas or deadly germs, Mr Ekeus had to recruit his own team of experts. He also had to raise money for UNSCOM, which ran well-staffed offices in Baghdad, Bahrain and New York. He was able to do all that because all the world’s main diplomatic powers (and generous sponsors of his work, like the Saudis) had the same goal in mind. Whether the same unanimity exists over North Korea is extremely doubtful.