THE new Reagan emphasis on peace through negotiation in Nicaragua is once again separating the President from his hard-core constituents, the conservatives. These are the Americans (a major portion of which vote Republican in presidential years) who think it unrealistic to believe that communists will ever give up their aggressive efforts to spread communism to countries around them. Thus, they see the United States abandoning the contras in exchange for, at best, empty promises from the Sandinistas that they will mend their oppressive, aggressive, communist ways.
These same hard liners were more incensed than other Americans over the administration's sale of arms to Iran. They couldn't believe in Iranian ``moderates'' any more than they believe in the Sandinistas bringing about lasting reform, and severing ties with Cuba and Moscow.
The President has received this message of outrage from those once viewed as Reagan loyalists. He has moved to quiet their fears - as he did last week in Los Angeles by meeting with contra leaders and pledging continued support for their cause. As a result he is sending out, as Sol Linowitz points out, ``mixed signals,'' the kind that dilute his effectiveness.
Mr. Linowitz played a leading role in bringing about the Panama Canal treaty under President Jimmy Carter. He still holds out hope that the presidential peace initiative, though now muted, will help end the conflict in Nicaragua.
Linowitz thinks the communists will continue to cause unrest in South America. But he does see the possibility that the Sandinistas might decide it is in their own self-interest to stop fighting. He says it's at least worth a try, and adds that President Reagan's long-expressed intention has been to bring about a peace through negotiation.
What caused Reagan's decision to endorse the peace plan initiated by Speaker James Wright, and say that a somewhat parallel proposal from five Central American presidents was a positive initiative?
The answer, say many critics, is that the President did this simply as a ploy in order to get Congress to agree to more aid for the contras. The ploy would work like this: The Sandinistas would fail to live up to the agreement - which would call for quick responses from both sides - and then the administration could go back to Congress with an argument along this line: ``See, the Sandinistas really don't want to negotiate. We must continue to put military pressure on them - and that means more funds for the contras.''
This rationale would suggest that the President is not sincere in his bid for a negotiated peace. This simply isn't so. He has been hit so hard by his own people that he has felt he had to reassure them and the contras, too. But, as people close to the President say, the real reason why Ronald Reagan has taken this surprising course is his conviction it could work.
He could see the contra-Sandinista struggle going on interminably - certainly beyond his remaining months in office. Mr. Reagan now is playing for history. He wants very much to see if he can't get peace to break out in Nicaragua during his watch.
Further, Reagan is convinced that his strong credentials among the anti-communists should help him (despite the initial protest from this quarter) to secure the public support his initiative will need. Reagan is reminded of how Richard Nixon opened up US ties with mainland China - and how it took an anti-communist president to make this move and still keep his strongly anti-communist constituents from seeing it as an act of disloyalty or even treason.
Well, Reagan's credentials with the anti-communists are not as good as Nixon's were. Reagan hurt himself among the right wing when he sent arms to Iran. Even before that, many hard-liners had been upset over Reagan's choice of top advisors (Howard Baker, James Baker, and Donald Regan, for example) who are not true believers. They deplore what they see as a circle of advisors who never let Reagan be Reagan. They also point to Reagan's flimsy support of the right wing's social program, which he had endorsed during both presidential campaigns, as another example of moderate Republicans ``controlling'' the president.
So now that Reagan is talking about negotiating with the communists in Nicaragua - instead of defeating them - these conservatives are not too ready to say, as they had earlier said with Mr. Nixon and China, ``Well, we don't agree with what the President is doing - but we can trust him not to be caving in to the communists.'' Reagan still has a lot of support and credibility with that element - enough so that, grumblingly, they will not bolt. So there remains bipartisan support for the Reagan-Wright initiative.
Reagan is not caving in. But he is playing to history - and his place in history.
Godfrey Sperling Jr. is the Monitor's senior Washington columnist.