IT'S INTRIGUING that the Soviets allowed Americans to inspect their radar at Krasnoyarsk. This is the one that Americans across the political spectrum have long agreed -- on the basis of satellite intelligence -- to be in violation of the 1972 Antiballistic Missile Treaty. No other arms control violation, real or alleged, has had the political resonance of this one.

It could not have been easy for Moscow to open up such a sensitive military site to a group including not only the Reagan administration's congressional critics but also a congressional staffer known for hard-nosed expertise. But whatever the Russians lost in military secrets they presumably figured to match, and then some, in public opinion by showing themselves ready to let Americans poke around and by showing the facility itself (reportedly shoddily built, low-tech) to be something less formidable than had been earlier imagined.

The Russians may have been right in this public relations calculation: there has been much oohing and aahing over the glasnost of it all. But there is also the troublesome matter of confirmation of a treaty violation, which previously had to be taken on official say-so. The ABM treaty binds each great power not to build a missile defense. In the special Soviet-American commission set up to handle compliance questions, the Soviets had said -- had lied -- that the facility was designed for space tracking. But this is not and never was one of those gray-area issues of imperfect evidence, imprecise text or disputed interpretation. The Kremlin is in violation. Rep. Tom Downey (D-N.Y.) (and his congressional colleagues) and House Armed Services staffer Anthony Battista confirm that the facility, once completed, is meant to serve one or another phase of missile defense.

Now what? One possibility enjoying early favor builds on the view that it is a violation but perhaps not a very important or threatening one, and therefore the United States should respond constructively and work out a solution with an obviously chastened Soviet Union. Moscow is ready: it would yield up Krasnoyarsk for two American radars in England and Greenland -- radars it didn't start complaining about until it was called on Krasnoyarsk.

It sounds constructive. But it makes glasnost not the servant of treaty compliance but a substitute for treaty compliance. Krasnoyarsk is no less a violation for being acknowledged, finally, by Moscow. What presents itself here is not something that needs to be resolved by the two parties but something that needs to be ended by one party. The radar should be dismantled.