From an American point of view, the highly publicized realignment of European currencies this week is much ado about nothing: It left untouched the key unstable global money relationship--the one between the dollar and Japanese yen.

The newly-agreed-upon European rates of exchange are likely to have only marginal results, if any, on U.S.-European trade.

At least, that is the view of hard-nosed analysts here and in New York, who believe that a critical obstacle to world economic recovery is an overvalued dollar, which encourages protectionism--a condition that the European realignment did nothing to alter.

"The currency changes in Europe were strictly a local issue," said Rimmer de Vries, vice president and economist for Morgan Guaranty Trust Co. "They were sensible for them but, if anything, the dollar comes out of it stronger than before."

The latest shift was the seventh realignment in the four years of the European Monetary System's existence--in each case, the French franc declining against the West German mark. Overall, the mark has been revalued a total of 31 percent against the franc in that time--in itself a commentary on the instability of a supposedly-fixed-relationship system.

There is agreement, however, that if there had been no compromise on exchange rates--with the result that the EMS collapsed entirely--it would have worked to the disadvantage of the United States. In that case, with European currency relationships free to fluctuate without restriction, France, Italy and some other nations might have imposed even stronger protectionist barriers than now exist. It would have created yet one more erosion of a crumbling world trading system.

Technically speaking, because the West German mark was revalued by 5 1/2 percent and four other continental currencies were boosted slightly as against three devaluations (including the French franc), European money on the average probably was revalued slightly against the dollar.

Thus, Treasury Secretary Donald T. Regan's first reaction was that the dollar might weaken a bit after the exchange markets settle down. But that was merely wishful thinking, market analysts say. "The secretary is just trying to talk the dollar down a little bit," former Treasury assistant secretary C. Fred Bergsten suggested in a telephone interview.

Wall Street experts scoff at the notion that the dollar might weaken in the absence of assurance that interest rates will come down further. They note that on the same day Regan spoke of a weaker dollar, Federal Reserve Board Chairman Paul A. Volcker was reliably reported to be "snugging up" Fed policy as a response to fast growth of the money supply.

Most international money experts think that the dollar will remain overvalued in relation to European currencies until there is a substantial change in the dollar-yen relationship. "You won't get a change in the dollar-deutschemark relationship until the dollar drops at least 10 percent against the yen," de Vries said.

Close observers of Treasury policy think that Regan would be happy to see a weaker dollar and a stronger yen, which would help to boost American exports and to diminish Japanese exports. "But this administration doesn't know how to do get that result," said one economist. "Regan might like to see some pressure put on the Japanese to expand their budget, but the Economic Council under Marty Feldstein says it's really an American problem."

Bergsten noted that, ironically, the yen--which hit a low point of 278 to the dollar on Nov. 4, 1982--started to strengthen with the inaugural of a new prime minister, Yasuhiro Nakasone. By the time Nakasone arrived for his visit in Washington early this January, the yen had strengthened to 227 to the dollar.

"Nakasone expected to get a barrage from the Reagan people on the need to push the yen even higher," said Bergsten. But strangely, he got none: The talk focused more on Japan's defense expenditures. After Nakasone went home, the yen weakened again--despite expected benefits from lower oil prices--to about 240 to the dollar.

"The yen is unusually weak," Regan said on Monday. "We're not quite sure why."