A YEAR'S further discussion of whether the Soviet Union is respecting its arms control obligations has produced more of a consensus than most people had thought possible. The release of President Reagan's latest congressionally mandated report on "Soviet noncompliance with arms control agreements" makes this clear.

The main thing that has happened since the last report is that public attention has focused on one alleged violation -- the Krasnoyarsk radar. Most of those who previously hesitated to call it a violation of the 1972 Antiballistic Missile Treaty (ABM) have stopped hesitating. It has become very hard to deny that the Soviets set out shortly after the treaty was signed on a course specifically blocked by the treaty, that they stonewalled through years of American efforts to induce them to admit it or correct it and persist on that course to this day. Fewer people remain to say that it really doesn't matter all that much and that, in any event, it's wrong to talk about it in public.

Some Americans feared -- others hoped -- that official efforts to nail the Kremlin on this violation would unravel the whole arms control process. This has not happened: President Reagan and the Russians are headed back to full-scale negotiations at Geneva. But there have been other major consequences. The American standards for verification of new agreements have been toughened. And major impetus has been given to the idea of an American defense against ballistic missiles -- this is the idea embodied in the president's Strategic Defense Initiative. Unlike the Soviet radar at Krasnoyarsk, this program, in its current, research phase, is entirely consistent with the ABM Treaty.

A few Soviets have hinted that, if Moscow felt it could avoid public embarrassment, it might find a way to halt construction on the radar or otherwise signal that it understood American sensitivities. But of course Moscow had years to do just that, and so far has chosen not to, even though it was being discreetly pressed on the matter by Americans of very different political persuasions.

Is there not someone in the Kremlin with the wit to recognize the immense Soviet interest in quietly unfolding a few tarpaulins at the Siberian construction site? What a pity that its political radar is so inferior to that huge electronic radar being built at Krasnoyarsk.