The victorious Allies tried to limit the size of the German army to 100,00 men and stop it possessing tanks, heavy artillery, aircraft, poison gas or a general staff. Similarly, the United Nations Special Commission (Unscom) has spent six years trying to eliminate Iraq's weapons of mass destruction - nuclear, biological and chemical - and the means to deliver them.
The UN in Iraq is failing now for the same reason as the Allies in Germany failed in the 1920s. Both the First World War and the Gulf war ended in armistices. In the first case, the Allied armies did not set foot on German territory. In the second, they crossed only a few kilometres into Iraq.
In both cases, the agreements that ended the conflict could be enforced only with the co-operation of the defeated state, which was bound to wait for a suitable opportunity to throw off the shackles on its sovereignty. The only real surprise in the present crisis with Iraq is that this has been so long coming.
The analogy goes further. Versailles could only last so long as the Allies were prepared to restart the war to enforce it. Otherwise they had to negotiate. The US and its Gulf war allies are now in the same position. Are they willing to restart the Gulf war in order to enforce the provisions that ended it? Saddam Hussein is betting that they are not.
Lesser military action will not do. Last year the Iraqi leader sent his tanks into Arbil, the Kurdish capital, in a surprise intervention in the Kurdish civil war. For six years the US, France and Britain had been flying air-patrols over Kurdistan whose unstated purpose was to deter any such Iraqi action. When it finally came, President Clinton - facing re-election - fired missiles at targets 500 miles to the south of Arbil. American television viewers were impressed by their government's resolution as they watched the missiles launched, but to Iraqis, both the government and its opponents, the affair was a demonstration of American impotence.
The Iraqi leadership has already calculated the odds. For several years, it has debated its response to arms inspectors. Some Iraqis, including Tariq Aziz, the deputy prime minister, argued in the past (ironically he is now the spokesman for the opposite view) that if Iraq played fair with Unscom then sanctions would end. Others, notably Uday, the son of Saddam Hussein, and his newspaper Babil, said that the US was determined to maintain sanctions whether Iraq gave up its strategic weapons or not. When Iraq said on 29 October that it was going to expel the American inspectors belonging to Unscom, it showed that Saddam Hussein had finally decided that Uday and other Iraqi leaders who thought like him were right.
There were other calculations involved. Iraq was clearly encouraged by signs of "sanctions fatigue" in the world in general and particularly in Paris, Moscow and Peking. American influence has ebbed a little in the Arab world because of its failure to broker an Israeli-Palestinian agreement since the Oslo accords in 1993. It may even be that Unscom was about to unearth some Iraqi weaponry.
In the past 18 months, unnoticed by the outside world, there has been a significant power shift within Iraq. Since he re-entered Kurdistan last year the Iraqi leader has started to re-establish his power in his three northern Kurdish provinces from which he withdrew in 1991. He forced the evacuation of one of the largest CIA networks in the world, in the biggest defeat for the agency since the Bay of Pigs. A little earlier a CIA-backed military coup was unmasked in Baghdad and its leaders shot.
These developments gave Saddam Hussein confidence. Obviously there is no comparison between the military forces he has available and those of the US. During the Gulf war, Iraqi anti-aircraft fire was almost wholly ineffective against allied aircraft and missiles. The Iraqi leader has 450,000 men and 800-1,000 modern T-72 tanks, but his most important asset is that he probably will not face a renewal of the Gulf conflict.
Much will depend on how Saddam plays his hand. In 1980, when he invaded Iran, and in 1990, when he invaded Kuwait, he mistook a short-term tactical advantage for a real change in the balance of power in the region. His judgement of domestic Iraqi politics is acute, but he often misinterprets how the world will react to his moves.
In the present confrontation he will be on strong ground if he tries to make concrete but limited gains. The political status quo of 1991 is looking tattered, but it is not yet on its death bed. A few missiles will not impress the Iraqi leader. A full-scale bombardment of Iraqi power stations and oil refineries might do so, but such a prolonged attack could not be launched without an international political consensus similar to that which existed before the Gulf war.
"We reject any promises or sweet words," said the Baghdad daily Babil yesterday, "unless they are stated in an official and clear document which guarantees two demands: neutrality of inspection teams and setting a time frame for lifting the embargo." It is unlikely that Iraq will allow Unscom to return without some progress on these fronts.
President Clinton is playing it cautiously. No doubt there is plenty of support in the US for punishing Saddam Hussein. He is the one remaining card-carrying demon - with the possible exception of Fidel Castro - in the American political cosmology. But this support might change if the US forces start suffering casualties.
The political status quo of 1991 in the Middle East can no more be maintained indefinitely than that of 1919 in Europe. It would be better to arrange for its orderly demise - and a new relationship between Iraq and the outside world - than to pretend that the accords that ended the Gulf War can be kept alive indefinitely.