THE REAGAN ADMINISTRATION is moving roughly, perhaps too roughly, to shape an overall policy toward the Soviet Union. It is fine -- overdue and necessary -- that the secretary of state has now dragged Soviet support of international terrorism out of the diplomatic closet and made it a matter for which the Kremlin must account. The problem lies in the indiscriminate quality of some of the things being said. Official criticism, however public and harsh, of specific Soviet conduct is different from a generalized, diffused attack on the Kremlin's nature such as Mr. Reagan leveled when he suggested Moscow will cheat, lie and "commit any crime" to promote "world revolution."

True, much in the record supports what President Reagan said. And it is well, in dealing with the Soviets, to be wary. But approaching international political relations strictly on the basis of a nation's supposed moral character invites a crusade in place of a careful policy. It is, in fact, what the Reagan people rightly perceived to be the flaw in some of the Carter administration's approach to "human rights. "A problem-by-problem, area-by-area approach may risk losing sight of the big picture and opening oneself to being whipsawed by Moscow. But a good-vs.-evil approach risks missing what legitimate opportunitiets for honorable accommodation there may be. By injecting his philosophy so explicitly into his diplomacy, Mr. Reagan feeds the forces in both Soviet and American opinion dedicated to confrontation alone.

Confrontation alone, after all, does not seem to be President Reagan's chosen policy. He repeated on Thursday his intent to start "discussions leading to negotiations" for a SALT agreement entailing an "actual reduction in the numbers of nuclear weapons." The day before, Mr. Haig had committed the administration to "mutual restraint" in both political and strategic affairs, including observance of the terms of the unratified SALT II treaty. These are reasonable considerations and their premise is that the Soviet Union is in certain circumstances an acceptable negotiating partner. Mr. Reagan undermines that premise by his sweeping attack on Soviet intentions.

Presumably the President misspoke when he said, in faulting the SALT II treaty, that it permits "no verification" of the number of Soviet warheads. The truth is that the SALT II obligation to keep missile telemetry unenciphered provides the best method available to verify the warhead count. But that was not the only doubt raised by his remarks on SALT.

Mr. Reagan proclaimed himself, not for the first time, a believer in "linkage." Who at this point is not a believer? The real issue is not whether to link -- but how. To what level must the Soviet Union diminish its support of terrorism, for instance, for Mr. Reagan to consummate a SALT agreement? Such questions are bound to force his administration back to the basic question -- the Carter question -- about SALT II itself: Granted, it is an imperfect agreement. But everything considered, is the United Stated better off with it or without it?