Soviet first-strike ability doubted

Moscow's nuclear arsenal is not nearly accurate or reliable enough to destroy American silos in a first strike, US intellgence sources said. Contradicting the Reagan administration's case for building MX missiles, the sources told Reuters news agency that US monitoring of Soviet missile tests showed that the missiles would not be able to wipe out the existing United States Minuteman force in the foreseeable future.

A source who has access to and has evaluated the top-secret test data said Soviet missile accuracy wasn't even within the ballpark of being able to launch a first strike. The data on all tests since 1978 of SS-18 and SS-19 missiles, the most advanced Soviet ICBMs, had been gathered by US satellites and ground stations, he said, adding that some of the Russian rockets were fired from a site in the Soviet Union north of Iran to Kamchatka, Siberia. Although the precise Soviet targets were not known, the source said, intelligence monitoring of missile radio-guidance systems showed the Soviet missiles wobbled excessively and were too inaccurate to hit close enough to US silos to destroy the Minuteman missiles.

One of the top private weapons experts, Kosta Tsipis of the Massachusetts Institute of Technology, told Reuters he is about to issue a study that also concludes the Pentagon has greatly exaggerated Soviet missile accuracy. President Reagan has warned repeatedly of a ''window of vulnerability'' that would allow the Kremlin to launch a first strike and destroy US ICBMs in their silos.