What Jimmy Carter said to Ronald Reagan in their private meeting at the White House the other day was not disclosed. But only a few minutes before Mr. Carter was to sit down with the President he talked with a group of reporters about what he intended to say.
Above all, Mr. Carter said, he felt this administration was not maintaining the ''proper balance'' in its conduct of foreign policy.
''The thing that concerns me most,'' he commented, ''is that the strength being exhibited by a powerful nation like ours must be balanced by the adherence to a commitment to peace, an adherence to a commitment to moral values, an adherence to a commitment to human rights, and an adherence to a commitment to control nuclear weapons.'' He added:
''Unless this balance is maintained, between in effect practical idealism on the one side, with peace and the control of weapons, with strength being exhibited on the other side, our nation is damaged in its image around the world.''
Mr. Carter said he is worried that war is too much on people's minds these days: ''Even two thirds of the American people are, according to a poll I saw the other day, thinking we are headed toward a war. I don't think we are - and pray that we are not.''
Mr. Carter indicated that the essence of what he was going to say to Mr. Reagan was that he should give more thought to waging peace, lest the United States indeed drift into war.
Asked if his speaking out at this time implied an interest in trying to return to the presidency, Mr.Carter said, ''I have no ambitions along that line at all.'' ''But I have the right and duty,'' he added, ''to express my opinion. And many of the issues I am discussing with you I intend to discuss with President Reagan.''
''For example,'' he went on, ''I think the worst mistake our country is making in international affairs is not ratifying the SALT II treaty. This is a treaty that was carefully negotiated. And if we ratify the treaty, it would send a signal to the rest of the world that this is a strong nation insisting on peace and the control of nuclear weapons.''
''I intend to make this point with President Reagan,'' he said. ''But I don't know whether it will have any beneficial effect.''
Here Mr. Carter elaborated on his comments about the Mideast that he had made in a joint interview with Gerald Ford aboard the plane returning from the Sadat funeral:
''There is no way in my judgment ever to have permanent peace in the Mideast and an assurance of peace for Israel without resolving the Palestinian issue.'' Presidents Carter and Ford had said on the plane that they favored US talks with the Palestine Liberation Organization. Mr. Carter now reemphasized that the talks could come ''simultaneously'' with PLO recognition of Israel's ''right to exist.''
Asked if he would be willing to play the role of a US mediator in the Mideast , Mr. Carter said this was ''awfully iffy,'' ''unlikely,'' and ''not proper.''
''We should have a very strong American presence in the peace talks,'' he said, ''to resolve questions of the West Bank and Israel's security, and in the future, perhaps, the Golan Heights.''
''But so far,'' he said, ''we have not done so. And I think that both the Israelis and the Egyptians are crying out for that sort of role.''
Was Mr. Carter about to try to persuade Reagan to give more attention to the Mideast? It seemed likely. It seemed possible, too, that Mr. Carter would suggest to him it was time involve himself in personal diplomacy, a la President Carter, in order to bring the spirit of the Camp David summit to fruition.
Near the end of the session, Mr. Carter moved into a somewhat lighter vein when he was asked how he had ''gotten along'' with Ford on the trip to Egypt. He laughed, saying, ''On the way over there, not very well. On the way back we got along great.''
''When we first got together, there were some uncomfortable feelings,'' he said, ''although we were polite. But on the way back we had a very good, I would say, reconciliation.
''We discussed past campaigns, our relations with one another. We had two meals together. And, really, for the first time now I call him 'Jerry' and he calls me 'Jimmy.' And in the future I would not be a bit constrained to pick up the phone and call him on a question or an issue. And I consider that to be a very fruitful result of the trip to Egypt.''
So it seems that Sadat's funeral not only brought three former Presidents together for an important trip but it also caused two long-time antagonists to bury the hatchet.