The Chernobyl nuclear accident has revived an unresolved question from a decade ago -- that of ``linkage.'' The question is whether Soviet behavior in one area should have consequences in another. Specifically, does Soviet handling of the Chernobyl disaster reflect upon its basic trustworthiness in such important endeavors as nuclear arms control?
The issue is likely to be thoroughly debated at the Western economic summit in Tokyo. Ironically, as the summit convened yesterday, Tokyo registered slightly elevated (though harmless) levels of atmospheric radiation as a result of the accident in the Soviet Ukraine.
Soviet television, on Sunday evening, showed the first moving pictures from the reactor site. It showed the damaged reactor building, and the largely deserted area surrounding the building. The pictures were taken from a helicopter. Some road traffic could be observed, but no humans or animals were seen in the footage.
Tass said ``reliable control'' was being maintained over the other three reactors at the Chernobyl site, and they had been halted.
The radioactive cloud from the reactor continued to disperse yesterday, affecting wider areas, but with diminished impact.
But the international political climate remains polarized. President Reagan, in a weekend radio address, stressed that the Soviets' ``stubborn refusal to inform the international community of the common danger from this disaster is stark and clear.''
``The Soviets,'' he said, ``owe the world an explanation.''
British Prime Minister Margaret Thatcher said Saturday that the incident had implications for nuclear arms control. ``If you find it very difficult to verify what has happened in a peaceful accident of this kind,'' she said, ``you have to be even more careful on the verifications procedure on armaments.''
West German Chancellor Helmut Kohl said his country will propose a new convention on nuclear energy, including on-site inspection of nuclear power plants.
The Soviets, for their part, hotly deny fault. Still, the very heat of the rhetoric seems a tacit admission that Moscow knows its basic credibility is under question worldwide.
Pravda, the Communist Party daily, accused the West of raising a ``cloud of propaganda'' in order to ``distract the attention of the world community.'' It bitterly criticized a ``campaign of fear,'' of ``fables and conjectures'' in the West designed ``artificially'' to present Chernobyl ``as some kind of international crisis.''
The official news agency Tass said the White House had raised a ``hullabaloo'' in order to cast ``aspersion on the Soviet Union, on its peaceful initiative, to call in question the very possibility of conducting talks and reaching agreement with the USSR.'' Some diplomats here see a grain of truth in Soviet charges that the seriousness of the accident may have been overstated in some Western news reports.
But one European diplomat notes that that was largely a result of the Soviet effort to manage news about the disaster, and the failure to provide thorough, timely information. ``They have themselves to blame,'' he said.
One of the main sources of official Soviet information on the disaster was not even in the country. The plain-spoken Moscow Communist Party chief, Boris Yeltsin, in Hamburg for a meeting of the West German Communist Party, admitted that the Soviet Union had waited two days before informing other countries about the disaster, but said the notification was prompt enough.
He also confirmed that some 49,000 people were evacuated from the area around the reactor, but did not know when they would return. Two people died as a result of the accident, 20 to 25 are seriously ill, and some 200 sustained radiation injuries, he said. The figures are in line with previous Soviet statements.
Mr. Yeltsin told the Associated Press that radiation emissions around the plant had decreased from 200 roentgens an hour Friday to 150 on Sunday. A reading of 150 roentgens an hour is considered very high.
The fire at the reactor is believed to have been smothered by dumping sand, lead, and boron -- which absorbs radioactive particles -- from Soviet Army helicopters. The area immediately around the reactor has apparently been turned into a sterile wasteland, fatal to animal and human life. Soldiers and emergency workers venturing within 19 miles of the plant must wear special protective clothing. Water in the area has been contaminated.
Nevertheless, Soviet Prime Minister Nikolai Ryzhkov and two other members of the ruling Politburo visited areas near Chernobyl on Saturday, according to Tass. It said the men had decided on additional measures to ``suppress the cause of the accident'' and ``normalize the situation in the area.'' It did not specify what those measures were. The men also met with evacuees and discussed provisions for shelter, education, and work for those uprooted by the disaster.
The visit was likely made to prove that officials were on top of the situation.