While President Carter warns Senate fence-sitters that they dare not vote against SALT II for fear of Soviet reactions, the Kremlin is risking the treaty's death to secure Soviet military dominance over all of Europe.

The secret dread of Carter's SALT sellers is that Soviet actions may kill Senate ratification of the Strategic Arms Limitation Treaty. Far from turning down the decibel level of its harsh attack against modernized nuclear weapons for NATO, the Kremlin shows every intention of increasing the volume.

Turning up the juice on its latest propaganda barrage -- so similar to the successful Soviet attack against the neutron warhead a year ago -- would incite predictable reactions in the U.S. Senate and quite likely tip the balance against the treaty. That might be characteristic Russian clumsiness, but the suspicion here is that the Kremlin consciously puts European supremacy ahead of SALT.

Carter is getting into this predicament: while his agents fan out across the Senate to argue with the rhetoric of near-desperation that fence-sitters must support SALT II, he is wholly unable to control Moscow's bullying assault against modernizing NATO's nuclear weapons.

The president's problem is one of dates. NATO is due to consider, and surely to approve, nuclear weapons modernization at a Brussels meeting on Dec. 13 to give the Western alliance equality with Warsaw Pact nuclear weapons. According to the optimistic SALT timetable of Senate Majority Leader Robert Byrd, the Senate then will be nearing a final vote on the treaty.

The escalating Soviet attack on nuclear modernization could not come at a worse time with regard to SALT. Led by President Leonid Brezhnev himself, the Soviet campaign reached a new peak Oct. 25 when Defense Minister Dmitry Ustnov accused the United States -- not NATO -- of "whipping up an atmosphere of fear, putting the arms race into a higher gear and openly conducting military preparations."

Such intemperate language is really directed not at the United States but at NATO's vulnerable European members. Yet its unavoidable side effect is to incite anti-Soviet anger in the U.s. Senate, tipping into opposition senators sitting on the SALT fence.

Against the Soviet campaign, Carter's SALT sellers are hard put to find an offsetting political argument, although they are trying desperately hard to win new recruits to the treaty.

On the evening of Oct. 22 Sen. Edward Zorinsky, a maverick Democrat from Nebraska who is the most junior member of the Senate Foreign Relations Committee, was telephoned at home by Majority Leader Byrd. Ostensibly, Byrd was asking when the committee might finish up with SALT; actually he called to gently pressure Zorinsky to get off the fence on the right side.

For Zorinsky, that was just more of the same. In three successive days, he was visited by elder statesman Averell Harriman, telephoned by Zbigniew Brzezinski, Carter's national security adviser, and importuned in yet another telephone call by Secretary of State Cyrus Vance ("Please, Ed, we need you").

The message is the same for every fence-sitting senator: vote for SALT to prevent Senate Republican leader Howard Baker's getting an advantage over Carter in his presidential campaign; vote for SALT so that our NATO allies will not feel the United States has deserted the road of detente; vote for SALT or "the Russians won't understand us."

Such appeals may well have their persuasive side. But Byrd confides to intimates that he is not close to the 67 Senate votes needed for treaty approval and that he may benefit more from guns than soft soap. Signals are coming from the White House of imminent concessions to Sen. Sam Nunn and others who demand higher defense spending in return for supporting SALT.

The White House scare tactic of warning Senators that defeat of SALT could spell the doom of NATO has backfired and is winding down under orders from the top. The president has been told that if SALT is not ratified, the warning could turn into a self-fulfilling prophecy -- leaving this country not only without an arms treaty but without a NATO alliance.

But substituting defense spending for scare talk will not help if the administration is correct in this private prediction: the Kremlin feels that forcing NATO to scrap nuclear weapons modernization is more important to Soviet ends than inducing the Senate to approve SALT. Seemingly, Moscow puts much more faith in weapons than in treaties.

An error in transmission of a recent column attributed President Carter's lack of support in Philadelphia to three years of "inflation"; it should have read "inattention."