The meltdown at the Soviet nuclear power reactor cannot fail to rain political fallout on the East-West strategic arms debate and perhaps, in Moscow, on much more.

There is a difference between a civilian accident and a deliberate military act, but the link is clear. The accident at Chernobyl is giving the Soviet and European publics directly and others indirectly the most authentic and bitter taste they have ever had of the experience of nuclear war.

This is no Three Mile Island, in which there was a nuclear accident and heavy expense but otherwise only a big scare. Here there are deaths, a plume of radioactive poison drift- ing over hundreds and hundreds of miles of settled land and across national frontiers, and a matching plume of imense medical, economic and political consequence, especially for Moscow.

The most urgent place where change may be registered is in the certainty that men can cope safely with the nuclear genie. Soviet arrogance, before the event, was undignation has been evoked by the fact that the energy monopolies, in chasing after profits, are not taking proper measures ensuring the safety of the functioning of nuclear power stations," a Soviet commentator said when TMI blew. "We have successfully established norms and rules for plant operation," the deputy chairman of the Soviet Committee on Peaceful Use of Atomic Energy added. "Soviet safety norms simply rule out any escape of radiation."

Not only the norms for power plants must be checked. So must the norms for nuclear weapons. The Reagan administration says it has taken important strides in this area, but it must see what further strides can be taken. There is no call for uncontrolled hysteria in review- ing the making and handling of nuclear arms, but some controlled apprehension could be useful.

I have a lonesome long-nursed thought here. What good reason is there for the nuclear powers to treat as secrets the safety features of their weapons practices? Cannot ways be found to detach and exchange some of this information?

A serious inquiry, of course, has to go beyond procedures and plans. The freshened sense of nuclear peril makes this an opportune moment to review as well the moral attitudes underlying strategic policy. Joseph Nye's new book, "Nuclear Ethics," is the right guide.

Nye speaks to people who are prepared to live with nuclear weapons and deterrence for want of a better alternative, but who want to do it correctly. He undertakes to write rules of the moral road -- examples: never treat nuclear weapons as normal weapons; minimize harm to innocent people.

The accident suggests a need for an additional moral rule: tell people when things go wrong. It is bad enough that the Kremlin, by concealing and delaying word of the disaster, inflicted additional suffering on its own hapless subjects. Withholding the word from affected foreigners was a hostile act, one that kept people from knowing of things vital to them and from doing what they could to make ready. None of this is to be excused as reflecting a supposedly inviolate cultural preoccupation with secrecy.

In part of the nuclear realm, through the Soviet-American hot line, Moscow has accepted an international responsibility for the timely communication of certain information. The principle must be extended.

Many people will probably find in the Chernobyl incident cause for new exertions in arms control. The effort may focus first on meeting Moscow's challenge to negotiate an end to underground nuclear testing, since testing suggests the menace of fallout.

It's somewhat illogical: there is no fallout from an underground test properly conducted. But testing -- whether it be on the modest scale justified by the requirements of stable deterrence or the extravagant scale contemplated by the Reagan administration's weapons plans -- will now be subject to a new burst of anti-nuclear feeling. It will not do to dismiss all of this feeling as an emotional reaction. To a point, fear is a sensible response to catastrophe. Business-as-usual detachment is a pose.

In Moscow, the disaster can only add to the considerations that were already summoning the Kremlin to concentrate on rebuilding at home. This is obvious. What is not so obvious is how Mikhail Gorbachev will handle his first genuine crisis. He is being blamed for a public-relations fiasco. This is among his lesser cares. He must organize a tremendous internal recuperation and find ways not simply to limit the damage abroad but also, if he is a true leader, to raise to a new level the international collaboration needed to make a safer nuclear world.