AMONG the beneficiaries of the late-winter thaw between the United States and the Soviet Union which began Feb. 28 with Mikhail Gorbachev's proposal for a Euromissile accord has been West German diplomacy. Bonn's ties with both the Soviets and East Germans appear likely to benefit. Christian Democratic Chancellor Helmut Kohl told the Bundestag this week that good relations with the Soviets are of ``central significance'' to West Germany. West Germany remains firmly anchored in NATO. But Dr. Kohl, newly reelected, is eager to prove that his party can do as well with the Soviets as can the Social Democrats, initial architects of Ostpolitik.
His remarks also, no doubt, reflect the views of his foreign minister, Hans-Dietrich Genscher. Mr. Genscher, whose Free Democratic Party showed particular strength in the January elections and who has held his job longer than Mr. Kohl has held his, has long supported good relations with the East and has been particularly supportive of late of Mr. Gorbachev's ``new political thinking'' and other apparent policy innovations.
Moscow will be quite interested in Kohl's speech. His speech to the Bundestag also called for an agreement to eliminate both Soviet and US medium-range missiles from Europe; this support comes even as the merit of such an accord is being questioned in the United States, France, and Britain. The Soviets will want to cultivate this support from Bonn.
Meanwhile, relations between the Germanys are moving into springtime, presumably with the blessing of Moscow. ``Upbeat'' talks between officials of Bonn and East Berlin were held at the Leipzig Fair, often a good barometer of inter-German relations. The two main issues at the moment are the celebrations of Berlin's 750th anniversary and the question of a visit to the West by East German leader Erich Honecker.
West Berlin Mayor Eberhard Diepgen has invited Mr. Honecker to West Berlin's festivities. An acceptance by Honecker would signal a degree of acceptance by the Soviets and East Germans of West Berlin's link to West Germany - something they have resisted doing.
Conversely, officials of the US, France, and Britain, which retain ultimate authority over West Berlin, have expressed concern that if Mr. Diepgen accepts Mr. Honecker's bid to East Berlin's celebration, that would constitute acknowledgment of East Berlin as a legitimate national capital - something the Western powers have been likewise reluctant to do.
The whole discussion has been further complicated by remarks by archconservative Bavarian Premier Franz Josef Strauss, of all people, that the status of West Berlin should not be allowed to become a ``sacred cow'' that prevents mutual visits.
Mr. Strauss, a proponent of close inter-German economic ties, has also revived speculation of a visit by Honecker to Bonn and, presumably, his native Saarland, now in West Germany, which he is said to be eager to visit. A previously scheduled visit was scuttled in 1984 because of Soviet pressure.
As always with such cases, there is a need to proceed with caution, but the opportunities for better relations are to be welcomed.