UNTIL VERY RECENTLY, the American position on foreign economic policy has been that, fundamentally, everything's fine. If there is anything at all that needs fixing, somebody else must be to blame -- such as the Japanese, for not buying enough American goods. The Reagan administration has adamantly refused, until this month, to acknowledge the enormous international trade disruptions and the distortion of the world's monetary system caused by Mr. Reagan's very large budget deficits. Those deficits and their effect worldwide have been a subject that the administration has not wanted even to discuss. But the administration's view now seems to be changing -- and changing very much for the better.

Secretary of State George P. Shultz, in a courageous speech in Princeton last week, talked candidly about these relationships. He went on to discuss what's now necessary -- reducing those $200 billion-a-year federal budget deficits that stretch out ahead as far as the eye can see. They are "simply not sustainable indefinitely," Mr. Shultz warned.

Reducing the deficit will ease all the other indicators of trouble ahead -- the dollar's overvalued exchange rate, the wave of imports for which the country is paying with borrowed money, the damage to American export industries. As Mr. Shultz noted, protectionism and beating on the Japanese won't do much to balance the country's trade accounts as long as the dollar is grossly overpriced.

But other countries have reponsibilities as well, he emphasized. The Japanese do have a responsibility to open their markets wider. Even more urgently, the Europeans are going to have to begin pushing their own economies to expand under their own power. Currently they are simply riding in the American wake and depending on their rising exports to the United States to lift their own incomes. That worked last year. It won't work next year, for the American economy is slowing.

Mr. Shultz's speech appears to mark a turning point of some importance in the American attitude toward the international economy, and a new willingness on the part of the Reagan administration to deal with it seriously. On the day after he spoke, Treasury Secretary James A. Baker III, in Paris, proposed a conference on the international monetary system. This reversal of longstanding resistance to that idea is further evidence that a broad reexamination is under way throughout the administration.

Next month President Reagan will sit down in Bonn with the heads of the six other major industrial countries' governments to talk about economic strategy. Mr. Shultz clearly has this meeting in mind, and has laid out a realistic and useful position from which to begin those discussions. But he has an even more important audience here in this country. American voters and taxpayers aren't likely to support any serious attack on budget deficits until their government tells them why it's necessary.