World scientists' call for arms control now

Now is the time to negotiate meaningful arms control with the Soviet Union. The Kremlin's aging leadership desperately wants an arms limitation treaty. Such an agreement would be a monument to President Brezhnev's career, demonstrating his claim to be a man of peace. More important, the two superpowers have reached a level of parity which makes this the optimum time for serious negotiations.

This was the conclusion of this summer's International School on Disarmament and Research on Conflict, a symposium involving 65 scientists from East and West Europe, the United States, the Soviet Union and the third world. The school is affiliated with the Pugwash conferences.

We focused on the nuclear balance, the vulnerability of US land-based missiles and limited nuclear war, disagreeing fundamentally with the Reagan administration's rearma-ment program.

In contrast to Reagan administration claims, the USSR is not in a position of nuclear superiority. Four categories generally regarded as measuring nuclear strength show the superpowers relatively equal, with the US at a slight advantage:

1. Nuclear warheads. The US is well ahead in this most important category with approximately a 10,000 to 8,000 lead;

2. Delivery vehicles. The USSR has 2,498, the US 1,944, but American missiles carry a larger number of warheads;

3. Throw weight. The superpowers are also relatively equal in payload with the USSR at 45 million pounds and the US at 40 million (including strategic and intermediate-range systems in the European theater);

4. Megatonnage. The Soviets are well ahead in explosive power, but their lead is offset by missile inaccuracy. In this critical area, they are about seven years behind the US.

There is no ''window of vulnerability,'' as asserted by the Reagan administration. This phrase refers to a possibility of the Soviets destroying our land-based missiles without directly attacking our cities. They could then dare us to retaliate in the destruction of ours. As a result, the Soviets could wipe out our missiles or blackmail us, it is claimed.

If one assumes that the Russians plan a first strike against US land-based missiles, even with two warheads committed to each silo, their probability of success would not be high. Some Soviet missiles would never lift off due to technical failures, while others would not strike the silos accurately enough to destroy them. Many incoming missiles would be deflected by blasts and radiation from previously detonated warheads.

Radar and satellite signals of incoming warheads would enable the US to launch targeted missiles on warning, before their destruction, and satellite photographs of increased Soviet military preparedness during a crisis would permit the US to respond in minutes.

All these factors indicate that the USSR would not launch a first strike without unacceptable levels of risk. A window of vulnerability simply does not exist. In fact, the USSR feels threatened by the accuracy, power, and invulnerability of our new Trident submarine missiles.

Despite the absence of a realistic first strike threat from the USSR, the US has changed its nuclear strategy from ''Mutual Assured Destruction'' to limited nuclear war. The former strategy was based on a mutual balance of terror, in which a nuclear aggressor would be devastated by a second strike. Thus it was suicidal for either country to start a nuclear war.

Today, the Reagan administration is pursuing a new strategy, limited nuclear war, claiming that it will counter the Soviets' alleged first strike capability. This is madness. A limited nuclear war assumes that the use of nuclear weapons could be managed with logic, precision, and restraint. Political leaders on both sides who didn't work together to prevent nuclear war could hardly control it through mutual cooperation after the war had started. To expect rational control while millions of people die is totally unrealistic. Nuclear weapons once used would be almost impossible to limit. The consequences would be a disaster the likes of which the world has never known.

The solution to the superpowers' quest for security is not more nuclear weapons or a limited nuclear war strategy. Security can be increased through arms control, not massive rearmament. With relative parity, even a slight American advantage, the US should negotiate seriously with the USSR for arms control, realizing that with weapons and security, less is more.