A U.S.-British attack on Iraq is clearly the world's most controversial idea at present. As time becomes increasingly short, let me suggest the best — perhaps only — way this war might conceivably be avoided and, as food for thought, offer the most compelling historical parallel.

It is quite true that the only way to ensure Saddam Hussein doesn't get more weapons of mass destruction and to remove those already in his arsenal is by defeating and displacing him by war. The alternative has been active, energetic and enforced sanctions, and punishment arrangements to slow down progress indefinitely while keeping Saddam weak and isolated.

That was what led the Clinton and Bush I policies.

In its first phase the current Bush administration favored that approach, calling it smart sanctions. Why did it change? The easy answer is the ideology of many high officials in the government. But that is too simplistic since almost all these people had earlier supported the old policy.

The answer, of course, involves three factors: the Sept. 11 attacks, further experience in dealing with Saddam and intelligence evaluations.

Yet perhaps the greatest cause of the high and urgent priority being given to attacking Iraq has been the erosion of the sanctions, European eagerness to normalize relations with Iraq and Iraq's return toward a full role in Arab politics.

In short, Americans lost faith in sanctions, leaving them with only the war alternative. Why did that happen, and is it too late to change the situation?

If the Arab world, plus France, Germany, Russia, China and others, had wanted to avoid what is happening now they could have, and should have, taken a very tough line on Iraqi violations and on keeping sanctions.

Why did they not cooperate more with the United States in the 1990s? Resolution after resolution was passed while Iraq was never punished. Instead, the opposite occurred; controls were lifted over time, giving every expectation that they would soon be off altogether, or remain so minimal as to be meaningless or easily circumvented.

So the option was — and still may be, though it is going to be too late in a few days — a credible, serious international effort to harass, block and punish Iraqi behavior at every turn.

Ironically, the more anti-war forces and governments say things like "Iraq doesn't have weapons of mass destruction," "It is cooperating," or "There is no proof of an Iraqi connection with international terrorism," the more the United States and those who agree with it become convinced of the need for war.

The world will never really implement sanctions and pressures and punishments, so war is the only solution. It is probably too late at this moment; but it wasn't a year or two ago, or even a few months ago.

What is the alternative to a U.S.-British attack on Iraq? An immediate U.N. resolution that takes a very tough stand on Iraq, accepts that Saddam has lied about his possession of weapons of mass destruction, sets a high standard for compliance and indicates the willingness of the United Nations to take military action in future.

That approach would make it credible for the United States to wait. Countries that oppose war now must indicate that they will not rule out this option in the not-so-distant future if Iraq's behavior does not change.

With a real multinational alternative and the strong sense of an international willingness to vigorously contain Saddam or fight him, the United States would have an attractive option not to go to war now. But if the only current alternative is the ineffective action on the part of other nations — including many who make it clear they are ready to drop sanctions altogether — the United States will go to war.

Perhaps the most interesting historical analogy I can think of, which I have never seen cited by anyone else, is the 1956 Suez conflict. In that year Britain, France and Israel, each for its own reasons, came to the conclusion that Egyptian leader Gamal Abdel Nasser was a threat to the region's stability and must be stopped lest he become leader of the entire Arab world and set off a series of wars, revolutions and coups.

Secretly, they decided on a plan to get rid of Nasser.

Israeli forces attacked Egypt, after which the British and the French came in as "peacemakers." Nasser would have been brought down in a couple of weeks more.

But he was saved by the United States, which believed — as opponents of an attack on Saddam do today — that his defeat at foreign hands would prompt anti-Western attitudes and radical upheaval in the Middle East. Washington was also operating in a Cold War environment, fearing the USSR would gain great advantage from these factors.

Of course, Nasser survived and did become the Arab world's leading figure. His example and intervention promoted successful revolutions in Syria, Iraq and Yemen, while his example brought coup attempts or civil wars in a dozen more. His behavior led to the 1967 war.

And despite the fact that he had been saved by the United States, Nasser promoted anti-Americanism throughout the region. The ideology he promoted — radical Pan-Arab nationalism — continues to dominate the Arab world 33 years after his death.

There are, of course, differences between the two situations. The United States and France have switched sides, the attack on Iraq is being organized publicly, Saddam's potential weapons of mass destruction are far more destructive than the fighter planes and tanks Nasser had bought from the Soviet Union.

Yet beyond that, the parallels are striking.

How would the history of the Middle East been different had Nasser been overthrown? It is, of course, impossible to say. It might well have been more stable and less extremist.

But thinking about that history might help clarify the current debate.