Reagan's dual image: dove on arms control, hawk on Central America

It begins to look as though America's Ronald Reagan is going to get his equivalent of British Margaret Thatcher's Falklands war. Mrs. Thatcher rode to certain election victory in Britain this week on the crest of a political wave that swelled up in part from military victory in the Falklands.

In a silly maneuver at the beginning of the same week, the junta in Nicaragua sent three American embassy officals packing home on an obviously trumped-up charge. This justified Mr. Reagan in closing down all six Nicaraguan consulates in the United States.

Thus Mr. Reagan's campaign against ''communism'' in Central America picked up speed and strength. It became more difficult for opponents of his Nicaraguan venture to stop it. They ran the risk of being called ''soft on communism'' in next year's election campaign.

Mr. Reagan may well get credit out of all this for reversing a ''communist trend'' in Central America. If he is as successful as Mrs. Thatcher, he might even see the overthrow of the Sandinista junta in Nicaragua and a return of the government there back into ''anticommunist'' hands.

This has also been the week that Mr. Reagan updated the US position on nuclear weapons. At a meeting of the National Security Council in Washington his acceptance of the recommendations of the Scowcroft Commission on Strategic Forces was made formal.

The US delegation to the just resumed strategic arms reduction talks (START) in Geneva will presumably now be instructed to aim at ending the current race in multiple-warhead intercontinental missiles. The idea of the commission was to try to get back to single-headed missiles, which would make the strategic balance less unstable. Soviets reluctant to go along with Reagan proposals?

Whether the Soviets are ready to move in the same direction is another matter. Mr. Reagan still wants a big cut in the number of land-based intercontinental missiles. The Soviets prefer their big land-based missiles to the less accurate submarine-launched type. They rely on the land-based variety much more heavily than does the US.

However, there is more flexibility in the new American position than in the previous one. The Soviets may well consider it worth their while to explore the depth and distance of that flexibility. They might even make some interesting counterproposals. At least, there is a possibility of new motion in the positions of the superpowers on this subject.

Previously, Mr. Reagan was proposing that each side's intercontinental missiles be cut down to 850. The Soviets are rated currently at 2,350. It is unrealistic to think that they would accept such a cut. Hence the proposal was as much propaganda as negotiation.

Mr. Reagan has now modified his position on the number of such weapons. His latest proposal is said to be 1,200 for each side. This is probably still well below what the Soviets would consider at this time. However, any change in the position of either side reopens the bidding.

The President's new flexibility puts him in the role of the man of peace in the East-West struggle. As the '84 election approaches, therefore, he may be positioned to get the best of both worlds: In the arena of global nuclear survival, he plays the peacemaker; and in the arena of communist penetration of the US backyard, he is the resolute defender of the nation. Year after Lebanon invasion, Mideast caught in stalemate

There has been no important change in the stalemated situation in the Middle East other than increasing questioning in Israel of Prime Minister Menachem Begin's policies. The invasion of Lebanon has passed its first-year mark without bringing decisive results. The Syrians have maintained a posture of hostility. This forces Mr. Begin to keep substantial Israeli forces in Lebanon at the risk of a continuing war of attrition.

There is doubt about the tenure of Yasser Arafat as leader of the PLO. The Syrians are in control of supplies to PLO units operating with Syrian troops. The Syrians are not fond of Mr. Arafat. Mr. Arafat may be ousted and a substitute more to Syrian taste found.

But this disunity within the PLO seems to have little relevance either to Israel or to Mr. Reagan's Middle East negotiators. It does not resolve the central question of the future of the Palestinians. Meanwhile, in Lebanon the issue is whether Mr. Reagan can persuade the Syrians that they can get more from Washington than from Moscow. Probably not.