The continuing plunge in value of the U.S. dollar in West Germany has German exporters crying "foul" and American GIs sarcastically asking, "Hey buddy, can you spare a Deutschemark."

Although the American dollar has been declining steadily in recent months on several European money markets, it is here in West Germany where the fall is most dramatic and the political and financial stakes are the highest.

West Germany's powerful Deutschemark has increased in value by about 18 per cent against the dollar in the past year, must of the rise coming in the past two months.

The ramifications are very large. They extend from West German steel, chemical, automobile and machine tool companies already reporting heavy declines in dollar sales as their products become ever more expensive on the key American market, to a sharp increase in emergency loans to hundreds of low-ranking GIs with families who have to fend for themselves on the expensive West German economy.

West Germany's merchant shipping industry, with 80 per cent of its business paid for in dollars, is also forecasting large losses.

Politically, the stakes are also very high for the Bonn government, which already faces about a million persons unemployed in a country in which one out of every five persons makes a living from the traditionally thriving and efficient export industries.

There have been severe fluctuations in the value of the dollar here before. In 1973, it dropped in value in relation to the mark even more sharply for a while, but then it recaptured much of what it lost.

What is different now is that virtually no one expects the dollar to regain lost ground and most guessing is focused on where it will level off. Many believe it will settle eventually at about two marks to the dollar, slightly below where it was today after another record plunge to 2.07 marks to the dollar. As little as eight years ago, the dollar was worth four marks.

Despite the problems, things are not all bad for the West Germans, at least on paper.

A cheap dollar means they can pay their oil bills in depreciated dollars as long as the oil producers don't raise the price because the dollar is so much cheaper. Cheaper dollars also mean the Germans can buy more stock in American companies and build more plants in the United States at bargain prices.

Yet, the current dollar-Deutschemark struggle cuts much further into real life than the complicated arithmetic of exchange rates and stock prices.

As West German exports get increasingly expensive, the risk of unemployment rising still further here also increases. Although the present rate of 4.4 per cent unemployed is well below U.S. levels, it is high by standards in Germany where fear of unemployment and inflation have been dangerous political issues since the economic disasters of the Weimar Republic in the 1920s and 1930s.

Furthermore, as the London Economist magazine recently pointed out, the dollar's sharp decline in effect punishes the most efficient German companies - since those are the ones able to compete in the U.S. market - and thus stifles the climate for badly needed new investment and employment at home precisely by the companies most apt to expand.

Most west German business leaders believe the Carter administration is waging overt war on the U.S. trade deficit of almost $30 billion by tacitly encouraging the dollar to drop and thus make American products cheaper overseas.

The Germans bitterly complain that the Carter administration is trying to make Europeans pay for America's gluttonous use of oil - which accounts for most of the U.S. deficit.

The Americans argued that much of the deficit and the high level of oil imports are the result of a U.S. effort to fuel its own economy more rapidly than the other economic powers - such as west Germany and Japan - in an effort to help pull the world out of a lingering economic slump.

It is an argument in which both sides are correct. Yet, the fact that nothing is happening and the dollar continues to slide here is giving rise to a second level of concern that goes beyond economics into the level of trust, at least in German eyes.

Germans, who tend to instinctly worry about everything, worry especially about signs of American weakness, and the slippage of the dollar is viewed as such a sign. The problem for Americans is to sort out that emotion from German special business interests who want to stop the slide because it is making their products too expensive.

The problem of trust, however, seems authentic. When the dollar slides for non-technical reasons, the influential weekly newspaper Die Zeit said recently, "the situation becomes dangerous."

"The Americans should not consider the heavy decline of the dollar merely as reflecting the technical situation of exchange markets," the respected Frankfurter Allgemeine newspaper editorialized last week.

"Drastic devaluation of a currency - even in a system of flexible exchange rates - reflects growing distrust of the country concerned. It gives rise to suspicion that here is something wrong about the economic and financial policies of the country concerned. Thus, the misery of the dollar is not only a result of America's great balance-of-Payments deficit," the paper said, "but, above all, a result of President Carter's vacilating and unclear attitude."