Whenever in our age a major villain appears in the center of the international stage, presidents and political commentators invoke Hitler and, sometimes for good measure, Munich and Chamberlain. It is in some ways only natural; Hitler was certainly a major criminal, a tyrant and aggressor responsible for the murder of millions of people. But he was, alas, not the only tyrant; there were a great many from Joseph Stalin to Pol Pot, and from Idi Amin to Nicolae Ceausescu.

They were all execrable, but each in a different way. The frequent invocation of Hitler, while psychologically understandable as a symbol, is not politically helpful. No one is more unhappy about this habit than the historians, who know that each historical constellation is unique, that it is fruitless to compare Germany in the '30s to Iraq in the '90s, that in brief, contrary to widespread belief, history does not repeat itself. At most it can be said, as Lord Acton once put it: The same -- always different.

Unfortunately, many of the arguments made by the other side in the current political debate are even less helpful. Unlike Hitler (we are told) Saddam Hussein cannot aspire to world power; if so, we may as well ignore him. But even Hitler wanted to make Germany only the predominant European power. Hussein, it is said, is not really dangerous because Iraq has only 17 million inhabitants, whereas Germany had 60 million (At the same time, the argument continues, one must tread very carefully because Saddam is the potential leader of 100 million Arabs. Let us disregard such contradictions for a moment.)

That Iraq has not the population and industrial infrastructure of a superpower is a matter of general knowledge. But whether a country is strong or weak is a relative statement. In the Middle Eastern context, Saddam Hussein has the strongest army. He has oil and non-conventional weapons. All this compensates, to a point, for his narrow power basis. True, Hitler also had non-conventional weapons, but he never envisaged the use of poison gas except on the home front: as a victim of a gas attack in 1918, he knew that it was a double-edged weapon. Saddam Hussein, it should be recalled, never saw active service.

Hitler was a pan-German. Saddam Hussein first appeared on the scene as a pan-Arab politician. His great hero is Nebuchadnezzar II, who was neither an Arab or a Moslem, but the builder of a great empire (and the conqueror of Jerusalem.) In 1987, in the middle of the war with Iran and other urgent preoccupations, Saddam invested much money, time and energy in rebuilding the royal palace in Babylon and other preparations connected with the celebration of the 2,500th anniversary of Nebuchadnezzar.

If he were to follow in his idol's footsteps, incorporating, say, Saudi Arabia, the United Arab Emirates, Syria and Lebanon, the population of his country would double. He would still not be in the Hitlerian league, but his power base would certainly be comparable to that of Mussolini at the time. He would be, in fact, in a better position because three-fourths or more of the Persian Gulf would be in his hands.

The differences between Saddam Hussein and the dictators of the '30s are still enormous. True, they all belong to a political culture that respects only force and despises diplomacy. But Hitler was an evil genius. The Iraqi leader has native cunning, but no more. Hitler and Mussolini were genuinely popular inside their countries. They were truly charismatic leaders, and their rule rested as much on propaganda as on terror.

Saddam Hussein cannot arouse the masses. His popularity is palpable, greater in Jordon and the West Bank than inside his own country, where it mainly rests on terror. His power base is too weak to cause more than regional mischief. He cannot build an empire. But given the vital importance of the Middle East, through his possession of an aggressive war machine and non-conventional arms, he can still create considerable havoc.

He is not a leader in the Hitlerian (Wagnerian) mold, envisaging, if need be, a Nibelungen finale, where everything goes up in flames. If he were a cleverer man, he would recognize the writing on the wall, which one of his predecessors (Nebuchadnezzar's alleged son) ignored to his detriment. But he is not that clever, and it is partly our fault for not spelling out clearly the punishment for crimes against humanity.

Historical analogies should be used with circumspection, and the same is true with regard to the lessons of history. According to experience -- from Napoleon's blockade of England to Rhodesia -- the prospects of the success of international embargoes are less than brilliant. But each situation is different, and the fact that a certain strategy did not work in the past does not mean that it will never work.

To give another example, the importance of air power was clearly overrated in World War II and Vietnam. But few countries are as vulnerable as Iraq to massive air attack, quite apart from the fact that the accuracy and destructiveness of bombing has greatly increased. It used to be said that generals always tend to fight the last war. Now the habit seems to have spread well beyond the military profession. The decision of what to do about Iraq ought to be based on an informed political calculus, not on doubtful analogies and lessons of history that are not apposite.

The writer is chairman of the international research council at the Center for Strategic and International Studies.