PARIS -- There in one frame of the political kaleidoscope are George Bush and Al Haig arguing over whether Europeans support the Euromissile treaty. Ronald Reagan appears in another frame to make a special speech to European audiences to reassure them about his handling of nuclear strategy. Another turn, and Margaret Thatcher is publicly telling her friend the president to pull up his socks and save the globe from financial disaster.

Interdependence. Ain't it wonderful?

Foreign policy and the global economy are now certain to play an inordinately powerful role in the 1988 U.S. presidential election. This could even be the election in which America says goodbye forever to the treasured notion that its national leadership contest is decided almost exclusively on domestic issues, with small regard to what the rest of the world thinks.

An accelerating crisis of confidence in Reagan's leadership grips Europe, and will become even more acute if clear signals do not come from Washington to steady the world's currency and stock exchanges. That is the sense of the grave warning Thatcher has given and chosen to publicize.

The Bush-Haig tiff over the missile treaty during the Houston GOP debate helped bring a previously unthinkable thought along these lines into focus: Their argument suggested that the candidates, and thus American voters, should actually care what Europeans think. That innovation is far more important than the merits of the argument over the treaty.

The same can be said of Reagan's decision to tape a speech for televising to Europe on USIA's Worldnet system but not for broadcasting in the United States. Going along to the U.S. Embassy here to watch a sparsely attended screening on Wednesday, I felt like something of an intruder as I listened to Reagan murmuring reassurances about nuclear strategy to a European audience.

What the speech did not say was as interesting as what it did say. Speaking to Europe, Reagan did not repeat his previous condemnations of nuclear weapons as an evil that must be abolished, nor did he refer to his promises to the American public to move beyond the strategy of relying on nuclear weapons to deter the Soviet Union from starting a war. His proposed Strategic Defense Initiative system of space-based missile defenses to render nuclear missiles obsolete got scant mention.

Instead, he declared that the forthcoming U.S.-Soviet missile treaty will actually "ensure the credibility of our deterrent" rather than weaken it. He welcomed projected significant increases in the nuclear arsenals of France and Britain, suggesting, I guess, that somehow these wily old Europeans have found a way to make nuclear weapons that are not evil. He warmly praised European efforts to expand conventional military cooperation.

To the extent it has any impact -- it was little noticed in the press here -- the speech will add to the confusion already apparent in Europe about what Reagan really thinks about nuclear deterrence and what he plans as the next steps after the medium-range missile treaty.

It was this broad unease with Reagan's nuclear strategy (rather than the narrow issue of the missile treaty disputed by Haig and Bush in Houston) that put the first cracks in the solid foundation that had underpinned U.S.-European relations in the first Reagan administration. Now, these cracks are becoming chasms under the pressures of the world financial crisis.

The clearest sign of how desperate things are came, appropriately enough, from Thatcher, who has become proficient at telling the American president how much she supports his arms control proposals and then quietly getting him to alter them. This time, she hit the alarm bell.

The Times of London, a newspaper that is both friendly to her and well-briefed by her office, in its Friday editions characterized Thatcher's telegram to Reagan as an appeal "to act swiftly to reduce his country's yawning budget deficit and to take charge of efforts to put the western economies back on an even keel." Her action, the newspaper noted in tones of shock, "represents a direct attempt to intervene in the domestic affairs of the U.S."

Will he listen to her once again? And, if he does, is he up to the task? Not even Thatcher pretends to know the answer this time.