Washington — Election season is seldom a time for serious diplomacy. President Reagan is no exception to the general rule that for an incumbent this is above all a time to avoid doing anything that roils the American electorate and to cast himself in the best light possible as a world leader and statesman.
Diplomatic and academic observers see the President now considering foreign policy questions largely in the context of the fall campaign and the November election date.
On the sensitive subject of arms, Mr. Reagan continues to say that he is seeking talks with the Soviet Union on antisatellite weapons. Fencing with Moscow in what has become a bewildering array of public and private exchanges, he seems determined to avoid a situation in which the US says no to a Soviet proposal to talk.
''Everything now is really looked at from the standpoint of how it effects the election,'' says David Newsom, director of Georgetown University's Institute for the Study of Diplomacy. ''The administration saw the Soviet offer as a way of putting the monkey on the Soviet back and of benefiting from a position of favoring talks while gambling that the Russians would not go along.''
White House officials admit that the mere fact of talking about negotiations benefits the President politically, even if the back-and-forth exchanges do not lead to actual negotiation.
Most political observers believe the economy - not foreign policy - will be the dominant issue in the election campaign. But Reagan political strategists are aware that some unpredictable event could change all that.
Also, they are sensitive to public opinion polls showing that the American people have concerns about the President's conduct of foreign policy. According to a Harris poll published in the current Business Week, 61 percent of Americans believe that the world is not a safer place and that the risk of war has not lessened as a result of Reagan policies. And 58 percent disapprove the President's handling of nuclear arms control.
It is partly in response to public perceptions of his militant anti-Sovietism that the President has adopted a more conciliatory posture in recent months. When the Soviets on June 29 proposed that negotiations begin in mid-September in Vienna on preventing the ''militarization of space,'' the Reagan administration responded positively.
Since then, however, a barrage of public and private exchanges has produced considerable ambiguity and uncertainty. Moscow seems to have been surprised by the affirmative US response and appears reluctant to move ahead, demanding that the US have a moratorium on the testing and deployment of antisatellite weapons. Experts say they believe the Soviets are caught on the horns of a dilemma, not wishing to help President Reagan politically but wanting to provide themselves a hedge against the possibility of a Reagan victory.
Washington, for its part, insists that it would raise the subject of strategic and medium-range nuclear weapons in such talks - something the Russians oppose doing. The fact that the administration did not mention space weapons in its initial proposal to the Soviets for an agenda leads some observers here to doubt that the administration is serious.
''If Reagan's task is to avoid talks without political damage, he's doing well,'' says Dimitri Simes of the Carnegie Endownment for International Peace. ''But if he's interested in talks, there's nothing for the Russians in this.''
In the Middle East, too, diplomacy is hostage to election politics. To the administration's relief, the last remaining US combat troops are quietly leaving Lebanon for home this week, enabling President Reagan to put a major foreign policy disaster behind him. Meanwhile, the President's peace initiative of Sept. 1, 1982, is all but forgotten. The whole Mideast question is on hold, not about to be resurrected in the heat of an election campaign when both Democratic and Republican candidates are vying for the American Jewish vote. The political uncertainty in Israel adds to the state of diplomatic inertia.
Aside from the arms question, Central America poses the most dangerous area for the President politically. According to a Harris poll, the vast majority of Americans think his interventionist policies in the region risk another Vietnam.Some 55 percent also oppose covert support for the rebels in Nicaragua.
On one hand, Mr. Reagan has adopted a posture of reasonableness, playing up US diplomatic efforts in the area. Last month the US and Nicaragua opened talks and representatives of the two sides have met three times. At the same time the President has not given up the basic thrust of his policy - military pressure on Nicaragua to combat what he regards as a communist threat on America's doorstep. Vice-President George Bush has signaled that the Republicans will make Central America a campaign issue, and Reagan is sounding the theme that he stopped the Soviets from gaining a base in Grenada and that the US has a responsibility to do the same in Nicaragua.
In the President's view, the Democrats fail to understand the communist menace. Political experts expect Reagan to use this issue as part of his strategy to paint the Democrats as on the extreme left ideologically and to woo conservative Democrats to his side who support administration policy.