For the second time this year, President Reagan has offered substantial concessions to put more flexibility and urgency into nuclear arms negotiations at Geneva. He is supported by NATO Allies. But the cold, hostile initial response of the Soviet Union to Reagan’s speech before the United Nations General Assembly cast new chills of discouragement upon a world looking for hope. The latest United States disarmament initiative comes at a point in history when humanity desperately needs a turnaround from the course of potential nuclear destruction being pursued through the arms race. But instead of seizing the moment for statesman-like leadership and joint cooperation toward ridding the world of a terrible cancer, the Russians brushed off as “nothing new” the President’s proposals to limit medium-range nuclear weapons in Europe. Then they used their news agency Tass to villify the President and accuse him of “demogoguery” and “blatant lies.” Reagan told the General Assembly that if the Soviets make concessions of their own, the Americans will consider a new ceiling on the number of U. S. missiles in Europe, reductions in planning deployment of the new Pershing 2 and cruise missiles, and companion curbs on numbers of aircraft. Details of course, would be negotiated. While making his new offer, Reagan reiterated that he believes his original “zero option” under which the U. S. would cancel the European deployment, planned to start in December, if the Soviets removed their 351 SS-20 missile targeted on Western Europe – is still the best plan. This obviously would be the wise course for peace and security of the people. But the Russians have once more declared they will not accept it. With their initial propaganda blast out of the way, it is hoped the Soviets will reconsider their hard line and measure up to the stature expected of a world power in the sobering talks with the U. S. at Geneva. A United Nations speech by Soviet Ambassador Oleg Troyanovsky, originally scheduled the day after the Reagan talk, has been .:est7 for Oct. 4. In the interim, Soviet leaders should develop a positive and constructive response to the American initiative that will help get negotiations on a fast track, As for the United Nations’ role in cooling the nuclear threat, the world body needs to be more united, aggressive and persuasive. Now is the hour for the forceful leadership envisioned in the U. N. charter.