Yet there are other illusions, almost as dangerous. The prevailing illusion, which the President has been fostering, is that the world has become a much safer place than it used to be. The President's European trip was presented in such a way as to encourage that comforting notion.
Cosy pictures of a jovial Clinton with a Yeltsin at least doing his best to smile carried the message that the Russians now love us and the bad old days are over. Signs that there is a great and growing number of Russians who don't love us at all, and yearn to return to the bad old days, are excluded from the world of presidential social calls.
A glaring example of escape from reality into a roseate world on that presidential tour was the case of the meetings with the President of Ukraine, Leonid Kravchuk, who promised to get rid of his country's nuclear weapons. In the atmosphere of the tour, the distinction between promise and fulfilment was ignored. So was the fact that Kravchuk had already made such a promise, and been overruled by his parliament. Nor could anyone possibly allude, in that euphoric atmosphere, to the forces that are beginning to tear Ukraine apart, with its nuclear weapons up for grabs between contending ethnically based military factions.
The President who promised, and the parliament which overruled him, and the country which both of them represent may all have vanished from the scene before the year is out. But for the moment, that most tenuous of promises holds the international stage. That last expression has become more than a metaphor, in the age of television. A pastoral illusion, conjured up by the camera, keeps grim reality at bay. One is reminded of Marie Antoinette and her world of make-believe in the Petit Trianon on the eve of disaster.
There was just one moment in the State of the Union message when the President took account, only implicitly, of the actual state of the world outside America. This was when he promised that there would be no further defence cuts. That sober and sensible promise was at variance, however, with the general thrust of his reassuring message.
The President is doing well, right now, in domestic matters, and stands high in the polls. Whitewatergate has not yet begun to hurt. But it is as a leader of the free world that Clinton continues to fail to impress. It is not just a question of conducting policy by photo calls, though that is a significant part of the trouble. More important is the fact that he has lost authority in the most vital area: that of defence.
He has done so as a result of his attempt to challenge the military establishment on the question of gays in the military. The military establishment is not normally a monolith, but an assemblage of competing factions. The fact that these groups have to compete for presidential favour in the allocation of resources and over senior appointments and promotions is a great factor making for health in the system, in the sense of maintaining the reality of civilian control.
But Clinton's profoundly misguided initiative on gays in the military had the effect of causing the establishment to close ranks against him, and to defeat him. As he retreated before a skilfully orchestrated public relations barrage financed out of the military budget, he sacrificed his Secretary of Defence, Les Aspin, who had tried to carry out his policy, and became his scapegoat.
When his choice as replacement, Bobby Ray Inman, withdrew on his own initiative, Clinton could think of nothing better to do than to nominate Aspin's deputy, William J Perry. The Pentagon indicated satisfaction. The whole protracted episode has seriously weakened presidential control over defence policy and therefore also over foreign policy.
The weakness is apparent in policy towards Nato and the Partnership for Peace idea. This is now taking the form of associating the East European countries with Nato, but not admitting them to membership in it. In an important article this week, Henry Kissinger has challenged this idea, urging full membership for those countries.
The case is a strong one. If, as is well within the bounds of possibility, Russia returns to an aggressive posture, the West will need to draw a clear line somewhere. It is not now doing so. 'Associated' status leaves the East European countries in a grey area. To Russian expansionists - clearly a significant force in the new Russian parliament - exclusion of the East European countries from Nato sends the signal that the West will not defend these countries if they are attacked. There is an ominous Korean precedent here. The US did not formally guarantee South Korea as it did other countries. North Korea, with Stalin's approval, saw this as a green light, and the Korean war was the result. A clear line was not drawn then, and is not being drawn now.
In general, the leadership of the West hardly seems in good shape to handle the great challenges likely to be coming from the East. European union is a myth as far as formation of foreign policy is concerned. American leadership under Clinton is a photocall facade, for the moment at least. It is likely that the eastern challenges, as they develop, will eventually produce a greater degree of Western unity and leadership. But the early stages of any new challenges may involve us all in some unpleasant surprises.