Despite the humanitarian success of Jesse Jackson's foray into Cuba, the United States looks at the diplomatic implications of the visit - and does not like what it sees.
Diplomatic and academic experts seem agreed that the black leader's solo diplomacy has redounded most to the benefit of Fidel Castro and has made it more , not less, difficult for Washington to deal with Cuba. It gave the Cuban leader an opening for a propaganda gesture and reinforced his view that he does not have to deal with the US government.
''You have to feel some sense of gratification that people have been released from prison,'' says Sol Linowitz, a Latin America expert who helped negotiate the Panama Canal Treaty. ''But as a mechanism for diplomacy (the visit) is a bad precedent. You can't afford to have individuals take on themselves the resolution of conflicts, because these conlicts can't be dealt with in context and countries will use someone like Jesse Jackson to their own advantage.''
''From a foreign policy perspective, it doesn't amount to a hill of beans,'' says Mark Falcoff, a Latin America expert at the American Enterprise Institute. ''I don't like off-the-wall personal diplomacy. . . . No individual can have credibility to negotiate substantive issues of foreign relations.''
As a result of meeting with President Castro, the Rev. Mr. Jackson secured the release of 22 Americans and 26 Cuban political prisoners being held in Cuban jails. The Americans were imprisoned on criminal charges, many of them for drug trafficking. After their arrival in Washington last week, six of the Americans were detained by federal agents and arrested on criminal charges ranging from drug offenses to parole violations, and taken to local jails. A seventh man eluded arrest.
The Cubans were given diplomatic visas before leaving Havana for US temporary entry. Federal officials said they would join families in the US and be given resettlement help by relief agencies. The 26 Cubans are only a handful of the hundreds who are still held in Cuban prisons on various political charges.
The administration has praised Jackson for a ''humanitarian accomplishment'' in securing release of the prisoners. President Reagan said on their arrival, ''I'm glad they're home.'' But he turned down Jackson's request for an immediate meeting to discuss his talks with Castro. Secretary of State George P. Shultz also declined to see Jackson, stressing that he saw no change in Castro's basic policies in Central America. The State Department criticized Jackson for assailing US policies while in Cuba.
But the Democratic presidential contender did meet with a high State Department official on Friday. Later he said the administration has offered to meet Cuban representatives in July to discuss the return of the 1,200 or so criminals and mental patients who came to the US during the 1980 Mariel boatlift. ''I hope President Castro will respond to these two dates immediately, '' Jackson told reporters.
President Reagan is said to be angry with Castro for choosing ''to inject himself'' into American politics by freeing the 48 prisoners.
Many observers suggest that it is the vacuum in US-Cuban relations that made it possible for Jackson to undertake his mission. If the United States had an active policy aimed at the normalization of ties, it is felt, the situation would not have arisen.
''It's hard to argue with success,'' says Sen. Clayborne Pell (D) of Rhode Island. ''The dicussions leading to the release of the prisoners emphasize the need for us to have more normal diplomatic relations with Cuba.''
''The administration provides an opening to initiatives like this when it has a totally inflexible attitude toward a country,'' comments David Newsom, director of Georgetown University's Institute for the Study of Diplomacy. ''This administration doesn't want any real dialogue, and the result is that you give openings to people who think they can accomplish something. People dealing independently may achieve short-term benefits but make it more difficult for governments to achieve long-term benefits.''
Specialists note that Castro has a long record of dribbling out concessions to American visitors, especially distinguished ones. ''So the administration is right in not attaching significance to this,'' says a former chief of staff of the Senate Foreign Relations Committee. ''But it is being much too standoffish in dealing with Castro. We have a fully staffed embassy in Moscow. Why not in Havana?''
Concern is also voiced that Castro plays on the pluralism of American society , using it as a tool that he can manipulate to his advantage. Says a former diplomat: ''There's a sinister aspect to all this, when someone from an ethnic group in the US permits Castro to play favorites among our own various national groups and to appeal to a particular audience in a way that is not helpful or appropriate.''