Soviet workers helping build a new United States Embassy here have walked off the job. The Americans say the dispute is ''contractual.'' The Soviets say on-site health is at stake.
But the real issue may be bugs: the kind that eavesdrop, not the kind that bite.
The catalyst for the walkout is an x-ray apparatus generally used in the West to spot possible structural flaws in buildings under construction.
The Soviet view, as relayed formally to the embassy here, is in effect: the Soviet surgeon general says working at an x-rayed embassy site can be hazardous to your health.
The Americans say that, with proper precautions, the apparatus is perfectly safe, and point to the continued presence of American workers on the sprawling work site, immediately behind the aging yellow apartment-style building long housing the US embassy. A US official adds: ''This is a contractual dispute with our Soviet employees, as far as we're concerned.''
But ''clearly,'' remarks one informed source, ''the machinery can also be used to detect other things - such as concealed listening devices.''
''Bugs are the main issue,'' was the forthright remark from one US diplomat, who has declined comment on the strike to reporters, to a West European colleague. Asked by the European whether the x-ray checks had turned up any listening devices, the American said he had no knowledge yet of the results of the testing.
Another US official also claimed no firm knowledge of the testing results, but added to a fellow Western envoy: ''I personally assume one reason for the Soviet workers' strike is that they (the Moscow authorities) have reason to suspect we'll find something they don't want us to.''
The dispute has not halted the x-ray testing, the present stage of which is expected to end next month, but has added another in a long line of delays to the multimillion-dollar embassy project.
A main issue has been ''reciprocity'' - diplomatic jargon for the schoolyard principle that if Johnny takes your baseball glove, you take his.
The Soviets, too, are planning to move into a new embassy in Washington. But in their case, the building is ready to go. The Americans, arguing that most of the delays on this end are the product of official or unofficial Soviets, say Kremlin diplomats can move into the new Washington embassy only when the Americans occupy their new premises in Moscow.
More than a few Americans here suspect that the x-ray dispute is only part of the long process of tit-for-tat over the new superpower missions. They point out that Moscow had agreed at an early stage of the negotiations on the new embassy to allow the x-ray test apparatus into the Soviet Union.
''They (the Soviets) may just generally be trying to make things difficult,'' one US diplomat told a colleague.
As for bugs, the official in effect said the Soviets surely knew that the testing equipment would look out for more than a misangled beam or loose joint. ''But sure, it's an issue: we have a few dozen US personnel supervising a few hundred Soviet workers. It's inevitable we can't watch them all the time.''
Whether there really are bugs in the new embassy is anybody's guess. But US officials do report that past sweeps of the current embassy have periodically turned up listening devices, at least one of which apparently had gone undetected for years.