Having shot down a Korean airliner, the Soviet Union appears determined to meet international protests by trying to shift the burden of fault to the United States. Its statement yesterday bristled with an evident intent to brazen it out. Some parts of the statement--that the airliner was flying without navigation lights, for instance--are directly contradicted by tapes of the Soviet pilots. The potentially most telling allegation--that the airliner emitted coded radio signals of a sort "usually used in transmitting intelligence information"--was vague and undocumented. The personal abuse directed at Mr. Reagan suggests that the Kremlin is reeling under the hard evidence made public, promptly, by the president and that it lacks confidence in its own case.

Why are the Soviets not seeking to cut their losses by admitting error and moving on with other business? Why are they acting in a self-indulgent, emotional and nationalistic way, one seeming to undercut the presumed Soviet interest in improving relations with the United States and Europe in particular?

Some part of the explanation rests on dim considerations of the Russian national psyche. The main part would seem to flow from a calculated political judgment. It is as though Mr. Andropov, once he realized an innocent airliner had been destroyed, took the course of least internal resistance: he decided to stand with the Soviet military and KGB against any other tendency to give priority to ties with Washington and the world at large.

In doing the easy political thing, the Kremlin has failed to act on the obligation of a great power to do in small matters what must be done to maintain an atmosphere conducive to working on the big matters: reducing the dangers of nuclear war and moderating political disputes. Thus has it taken upon itself the responsibility for whatever degree of greater freeze in Soviet-American relations may now ensue.

The president's television presentation Monday was at once firm and restrained. He supplied the details and analysis to bulwark the nation's collective outrage, but he did his part--even if Mr. Andropov has not done his--to keep this country on the important arms control negotiating track. That he confined the action items to civil aviation measures within the political range of many different countries was sensible and not a little courageous, given the bitter disappointment felt by so many of his political supporters.

We thought he stretched awkwardly and unnecessarily by making a pitch for the MX: the shock of Soviet conduct and his own measured handling of the crisis are likely to firm up support for his defense projects anyway. Meanwhile he is right to keep leaning on Moscow, with facts, for a fuller and more forthcoming response.