THE TRADE EMBARGO that President Ronald Reagan dropped on Nicaragua as he headed out on his European trip has, so far, hurt him more than what the State Department calls the "target country."

Reagan's action had the immediate, predictable outcome: the Europeans were disgusted. Even Helmut Kohl, Reagan's faithful German shepherd, could not heel. Italy promptly announced plans to go ahead with a $25 million power plant project in Nicaragua. Latin-American countries rallied to their sister nation.

When Langhorne Motley, the assistant secretary of state for inter- American affairs, was asked at a House hearing what countries do support the embargo, he said "El Salvador," a reply which caused some hilarity. He would, he said, truculently, provide a list of others for the record.

No one thinks, however, that the catcalls will change Reagan's mind. His visit to Bitburg proved that he doesn't mind isolation. Besides, his stubbornness is a pillar of American foreign policy. Secretary of State George Shultz said that "perception of American weakness" -- which seems to mean Reagan changing his mind -- is "the most destabilizing factor on the global scene."

At home the reaction is not perceptible. The majority of American citizens have tuned out Reagan's premise that Nicaragua is picking on us. Besides, many were emotionally watching retrospectives on two wars, World War II and Vietnam, the one an engulfing tragedy, the other a mistake of a kind that we may repeat in this hemisphere. Nobody noticed the "national emergency" that the president claims propelled him to act.

At the hearing where Motley spoke, witnesses from Treasury and Commerce gravely analyzed the effects on our budget deficits, our foreign trade and unemployment figures. They assured the members that the United States will survive a loss of trade with a beat-up little country the size of Iowa.

No one mentioned the impact on the Nicaraguans. The fact that the people who don't have much to eat anyway now will have less did not come up. Apparently someone at the State Department gave fleeting thought to the prospect that Reagan might be seen as taking bread from the mouths of hungry children. The problem was dealt with in summary fashion under the familiar rubric that nothing Reagan ever does causes human suffering. A spokesman put out the word that it was not his fault.

"Responsibility for the current economic plight rests squarely on the shoulders of the Sandinistas . . . . We are not to blame."

It is possible that Nicaraguans will dutifully rail at Daniel Ortega for their new deprivations and specifically exclude Reagan from their curses over the lack of spare parts when their tractors break down. They have their instructions.

Reagan may indeed have had no rancor in his heart against the people of Nicaragua when he imposed sanctions. He was really furious at the House of Representatives, which had had the effrontery to turn down his request for humanitarian aid to the contras, who are contributing so materially to the inhumanity in Nicaragua. The House, in turn, was busy fashioning a suitable punishment for that other hardheaded traveler, Daniel Ortega, for his untimely trip to Moscow. Members were so "embarrassed" by Ortega's insensitivity to their feelings that they are going to vote for contra aid as soon as they can.

The next time Reagan's feelings are hurt, he probably will put a ban on U.S. travel to Nicaragua. Thousands of Americans have gone there to see "the threat" for themselves. Fear for the national security is alleviated by first sight of Managua, with its endless vistas of vacant lots, and evaporates totally on touring a countryside replete with shacks, ragged peasants, mangy dogs and spavined horses.

The Reagan administration has attempted to discourage these encounters with reality. FBI agents contact returning travelers with chilling requests to visit and see their slides. They make sure that the tourists have not brought back any Marxist-Leninist lice in their luggage.

Actually, the appeal of the Nicaraguan for the American is not primarily ideological. The country needs everything that we are good at -- roads, bridges, factories, schools. And it is starting over, which we once did, long ago.

As long as these excursions continue -- and sponsors report no dropoff yet in reservations -- we can hope that some factual element may creep into the dialogue.

Meanwhile, Washington is practicing what Rep. George Miller (D-Calif.) calls "the politics of bruised egos." That means it is not important if you occasion starvation or even war. What matters is that people know how much your feelings have been hurt.