The failure of President Carter's tardy rescue mission in Iran continues the dismal erosion of U.S. alliances and decline of American influence in Western Europe, threatening even to drive West Germany into semi-neutralism.

The rescue mission's failure multiplied Bonn's unease about close ties with a U.S. government that seems unable to do anything right. It dramatizes the shift in the balance of military power toward the Soviet side.

Beyond incompetence and weakness is a question of deceit. When he was pressing U.S. allies to join anti-Iranian sanctions as a non-military option, had Jimmy Carter already decided on the military rescue? The evidence that he had builds anger in European capitals -- especially Bonn.

One week before Carter dispatched the giant helicopters and transport planes deep into the Iranian desert, a senior foreign policy adviser to Chancellor Helmut Schmidt sounded a blunt warning. During our reporting trip through West Germany, he told us that unless the United States gives Bonn its head on detente with the East, the North Atlantic alliance cannot survive in its present form.

"If our window to the East [the Soviet Union and East Germany] closes because of American actions taken without our agreement, NATO will never be the same again," this official said in a confidential talk. While not claiming to speak for Schmidt, he often receives the chancellor's convictions.

Last Friday, West German television pulsed with anger and ridicule at the failed rescue operation. What galled the Germans was the contradiction between the U.S. troops, wearing regulation U.S. Army camouflage uniforms, and Carter's pledge ruling out military action if the allies went along with the United States on diplomatic and economic sanctions.

Thus, Carter not only failed to free the hostages but strengthened Western European assumptions about the dangers of being led through international minefields by Uncle Sam. The worst of these dangers, as viewed by the Schmidt government, is to let the United States limit West Germany's right to deal with the Soviet-controlled Eastern bloc.

It is not the rescue operation itself but its lateness that so disturbs U.S. allies. Even left-wing members of Schmidt's Social Democratic Party told us Carter should have ordered a clandestine operation to pluck the hostages out of Tehran immediately after the embassy was seized.

Their rationale: the crisis had to be ended, one way or the other, and quickly. To allow it to fester, as Carter did for six months, increased the risk each day of losing access to Iranian oil -- and making Soviet intrusions more likely. This last prospect fed European worries about following Washington's lead into what they see as a new cold war.

The United States has been putting more each day on its allies to help punish Iran. Because it has been paramount in Carter's presidential campaign, the hostages issue has dictated U.S. policy -- whatever the cost in oil to NATO allies to whatever the gain in influence to the Soviet Union.

While understandably keeping the clandestine operation secret from both allies and Congress, the president had been letting out tips that it was on his mind. One came when he relayed to Pennsylvania editors unsubstantiated reports that Ayatollah Khomeini would keep the hostages through Election Day. Another came when he told Walter Cronkite on CBS that the hostages were now in danger from the Tehran mobs.

But there were no hints to U.S. allies. In this moment of humiliaton, when intimations of weakness merged with uncharacteristic American incompetence, angry men in Bonn and elsewhere on the continent believed Uncle Sam also had turned deceitful.

While careful politicians greeted the tragic event with sober expressions of grief, the inquest will come quickly by members of Congress angered at not being told the secret details of the failed mission at briefings last Friday morning. Was the operation really doable? When was it actually decided upon? Did the helicopter failures stem from haste or shortage of equipment? Most important: did the president soberly consider what he was doing to the parlous state of the Western alliance?