January 16, 1986

''Ultimately, the great lesson of Martin Luther King, Jr.'s life was this: He was a great man who wrested justice from the heart of a great country - and he succeeded because that great country had a heart to be seized.'' - President Reagan. [ A14:4. ]

Seven years ago, Benetton, the Italian-based chain of midpriced apparel stores, had yet to enter the United States. Today, it seems to be everywhere. Since opening its first American store in late 1979, the company has grown to 400 outlets nationwide, with 25 of them in New York City and 6 of those on Fifth Avenue between 34th and 53d Streets. That kind of proliferation is not an accident. At the heart of the company's philosophy is the belief that its stores, filled with brightly colored sweaters, shirts, slacks and accessories, should be clustered as close together as customer traffic allows - a sharp departure from the prevailing gospel in the industry. ''We don't feel that our stores are in competition with one another,'' said Francesco della Barba, executive vice president of Benetton Services Marketing, the New York-based headquarters for Benetton in the United States. ''The stores are each based on a different look, aimed at a different target. In theory we can put two stores next door to each other.''

Mikhail S. Gorbachev proposed a broad timetable today for the elimination of all nuclear arms by the end of the century and announced a three-month extension of the Soviet moratorium on nuclear tests. But the Soviet leader declared that his disarmament process could start only if the United States joined in renouncing the testing and deployment of what he called ''space strike weapons.'' That is the Soviet reference to President Reagan's research program on space-based defenses. Mr. Reagan has repeatedly insisted that the space defense program, popularly known as Star Wars, is not negotiable, and the dispute has blocked substantive movement at the Geneva arms talks. [ In Washington, Mr. Reagan said he welcomed the Soviet proposal and would study it carefully. Page A10. ] Geneva Talks to Resume Mr. Gorbachev described his proposal as the most important of several foreign policy decisions made by the Politburo at the start of 1986.

Secretary of State George P. Shultz said today that the United States ''cannot wait for absolute certainty and clarity'' before using military force to strike at terrorists or countries that support them. He also seemed to take issue with the view of Prime Minister Margaret Thatcher of Britain that such retaliation would violate international law. In a speech at a military installation here in which he repeated his call for tougher American responses to terrorism, Mr. Shultz did not specifically criticize President Reagan's decision nine days ago not to use force against Libya. The Administration says Libya supports the Abu Nidal group, which American authorities believe was behind the attacks Dec. 27 at the Rome and Vienna airports, which left 19 dead, including 4 gunmen.

International A plan to eliminate all nuclear arms by the end of the century and a three-month extension of a Soviet moratorium on nuclear tests were proposed by Mikhail S. Gorbachev, the Soviet leader. A statement by Mr. Gorbachev also included what diplomats said was a potentially new Soviet stance on medium-range arms in Europe. [ Page A1, Column 6. ] President Reagan welcomed the comprehensive arms-control plan suggested by the Kremlin and said the Administration would study it carefully. [ A10:1-4. ]