Dominican Republic - In 1965, when this caribbean nation was reeling from civil war and U.S. troops occupied the capital, Deputy Secretary of Defense Cyrus Vance visited here as part of a mediating team whose goal, at least temporarily, was the installation of Antonio Guzman as interim president.

Today, Secretary of State Vance returns to the Dominican Republic heading the U.S. delegation to Guzman's presidential inauguration.

Times have changed since the first visit. The effort to install Guzman as a compromise candidate was unsuccessful, but 12 years of peacefollowed anyway as Joacquin Balaguer was elected for three straight terms with U.S. blessings.

Perhaps the biggest chance of all, however, is that today's inauguration marks the first peaceful, constitutional change in government that the island republic has seen in this century.

It is a victory not only for Guzman's Dominican Revolutionary Party and its backers but also in some measure for the Carter administration, whose support of the Balaguer government threatened to belie its professed commitment to democracy in Latin America.

Although the opposition had repeatedly charged Balaguer, and the Dominican armed forces, with upholding his mandate through force and corruption, Carter had congratulated the 70-year-old president last September for transforming the nation of 5 million persons into a "model" democracy.

That image was shattered during elections three months ago when the Balaguer government, badly trailing, stopped the vote count with guns. An apparent coup attempt was aborted following strong demestic and international pressure.

Carter avoided possible damage with a quick show of support for President-elect Guzman, accompanied by a threat of U.S. sanctions should Balaguer persist.

To reinforce the message, Carter has spent what is perhaps the highest level delegation of the approximately 50 present for the inauguration. In addition to Vance, the delegation includes U.N. Ambassador Andrew Young and newly installed assistant secretary for Lating American Affairs, Viron Vaky.

Perhaps the clearest message of all, however, is the presence of Maj. Gen. Dennis McAuliffe, chief of the U.S. Southern Command in Panama, as part of the delegation. According to one U.S. official, McAuliffe's message is directed toward a "special audience" - the Dominican military.

As a result of the Dominican general's known unhappiness with Guzman and their proven penchant for heavy-handed control, the official said, the military needed to be told that the U.S. armed forces stood behind the democratic aims of their president.

While some local business and political leaders expressed anger at the implication of McAuliffe's presence, it didn't seem to bother Guzman. The president-elect met with the U.S. general for nearly an hour at his home yesterday, and willingly posed for photos for the local and international press.

Guzman, 57, is a cattle rancher. He remained in opposition after the 1965 Vance mission quickly discarded the possibility of his presidency as unworkable. Having finally won the electoral battle, he clearly feels he will need friends in presidential power skirmishes to come.

In the several weeks since Balaguer's concession of defeat, the president and his Reformist Party have, through new legislation and presidential decrees, gone about changing the law to make things difficult for Guzman.

The changes began several weeks ago when the Balaguer appointed electoral commission arbitrarily awarded four Senate seats won by Guzman's party to that of Balaguer, giving a legislative majority in the upper house.

The current legislature, fully controlled by Balaguer, raised military pay and froze in place for two years the current list of commanders in a bid for armed forces loyalty to the Reformist Party. The old legislature also removed from the presidency the power to appoint judges and members of the Dominican equivalent of the U.S. Federal Reserve.

To add insult to injury, while Guzman party workers have spent the past week painting curbsides and buildings to welcome the slew of international visitors, Balaguer's sanitation workers have stopped trash collection and Santo Domingo's streets are filled with garbage.

Nevertheless, the Euphoria and excitement of the moment and the prospect of possible substantive change seem to have over come, at least temporarily, the anticipation of problems.

Newly elected legislators for the future in thoughts of eagerly anticipate legal and legislative battles with the outgoing rulers. Lawyers say they now will have a chance to press their claims through legal briefs and congressional arguments rather than facing the possibility of violence.

The inauguration of a new president is a novelty that will be sometime wearing off. Gathered around the garage of Guzman's modest residence here yesterday, the local press spent an hour photographing the change of license plates on Guzman's newly shined limousine.

For the first time this century, a freely-elected president received the "President of the Republic" number one plates from an elected predecessor.