PARIS -- "Strange climate," a Frenchman aboard a jetliner rising above Washington tells a fellow outbound passenger. The comment does not refer to the wilting heat of July in the Federal City. Instead, the departing visitor speaks of our slowly vanishing president, of our national preoccupation with Oliver North, Fawn Hall & Co., of our bemused Congress -- in short, of the disorder that the Iranian revolution and our botched attempts to deal with it have spread through our system of government.

What to do about Iran, about the cyclone of hatred and fanaticism that whirls out from its borders, about the foreign hostages whose fate Tehran may control? Oliver North's testimony this week was not the only event to show that western democracies as a whole have failed miserably in either confronting or co-opting Iran.

France and Iran are engaged in a tense standoff over French demands to question a suspected Iranian terrorist hiding in the Iranian Embassy here. Iranian police surrounded the French Embassy in Tehran. Prime Minister Jacques Chirac, who until recently sought to negotiate a "normalization" of relations with Iran and the release of French hostages, threatens now in exasperation to break off relations altogether and has asked publicly when Iran would begin to respect international law.

Britain, meanwhile, has completed the withdrawal of all but one of its diplomats from Iran in a dispute that also had raised the specter of new diplomatic hostage-taking in Tehran.

And yet, back in Washington, North was walking through another version of why he eagerly shipped Hawk and TOW missiles to the same ayatollahs in Tehran who had blessed the taking of the American Embassy in 1979. His patriotism, the risks he took and his concern for the hostages justified everything, he seemed to argue.

That was the important difference in what was happening in the three capitals. Both the French and British appear chastened by the lack of realism they showed in trying to work out separate accommodations with Iran's unrepentant revolutionaries.

French officials have now concluded that it was pointless, and counterproductive, to try to negotiate with Iran's "moderates." The Iranians, in the words of one senior official, "have a superiority complex, and want to see the Americans, the Russians and the rest of us on our knees before their revolution."

But in Washington, North's bravado on Capitol Hill and President Reagan's deliberate evasion of the chilling implications of North's testimony suggest that the men who mounted and tolerated this scandal have not learned that lesson, or little else, from the shame and disaster visited on the White House.

North sought to concentrate attention on the "neat idea" of fighting the Sandinistas with Iranian money, and on the very concept of covert actions, rather than focusing on his extraordinarily stupid, dangerous and self-defeating wheeling and dealing with Iranians who rejoiced in humiliating not just North but the United States when they had finished using him.

"I'd have offered the Iranians a free trip to Disneyland if we could have gotten Americans home for it," North told the congressional committees. That is exactly what he did: He took the Iranians to his own Disneyland of policy making, where the hostages would be freed, the course of history in the Persian Gulf would be changed, and he actually would be the national hero he still imagines himself to be.

Ultimately, Reagan pays the price for this fantasy, and for doing the one thing even he could not get away with. In mounting a covert operation to send arms to Iran, Reagan lied to his own constituency. He used secrecy to fool the people who had voted for him to do just about anything but arm the ayatollahs.

One way Reagan pays for this is in the confusion and controversy that surround the unexceptional White House plan to reflag 11 Kuwaiti oil tankers with the Stars and Stripes. It is a modest proposal that in itself should not cause the handwringing now being observed on Capitol Hill.

But there is legitimate suspicion that the White House is advancing the reflagging operation as yet another inadequate answer to that much broader question of what to do about Iran. As the Iranian attack yesterday on a tanker heading for Kuwait undoubtedly was intended to emphasize, it is a plan that leaves Iran with the initiative. But in Washington's "strange climate," Congress can do no more than watch, like a bird transfixed by a snake, as the administration inches further into harm's way.