Soviets Also Sent Banned Missiles to Bulgaria : Arms control: The move, revealed in a note to the White House, calls Moscow’s ‘good faith’ into question.

The Soviet Union has told the United States that it transferred SS-23 missiles to Bulgaria, as well as to Czechoslovakia and East Germany, before signing a treaty that bans the weapons from U.S. and Soviet arsenals, a State Department official said Monday.

Bulgaria has yet to confirm the transfer, which Moscow disclosed in a note to Washington within the past few days, the official said. The other two Warsaw Pact nations have acknowledged possessing the weapons, which were banned by the U.S.-Soviet Intermediate-range Nuclear Forces (INF) Treaty of 1987.

The clandestine transfer of the SS-23 missiles is fast becoming a significant and contentious issue in arms control relations between the superpowers. It raises questions of Soviet “good faith” in failing to reveal the transfers until challenged by the United States, U.S. officials say.

The U.S. inquiry to Moscow and other Warsaw Bloc nations followed announcement by East Germany’s new reformist government that it possessed 24 of the missiles and was scrapping them. U.S. spy satellites and other sophisticated detection networks had not uncovered the weapons on their own.

U.S. officials are searching for ways to preclude such surprises after the anticipated strategic arms treaty, which would slash arsenals of intercontinental nuclear missiles by 50%, is signed late this year. Congress is certain to ask for such assurances during ratification of the treaty.

The Administration is waiting until it has all the information about all the missiles before deciding how it will handle the situation and its ramifications, officials said.

If no legal violation of the INF treaty occurred, Washington would technically have no recourse either in law or within the terms of the treaty on the surreptitious shipments of SS-23s.

For future agreements, one possibility would be to seek specific assurances written into the strategic treaty that each side fully disclose the transfer of treaty-limited weapons or associated equipment to a third party.

But the United States has been very careful to avoid any such language in past arms agreements that would reveal information about or in any way infringe upon its military relations with allies, particularly the smaller nuclear powers of Britain and France.

In fact, one senior Administration official said, the U.S. negotiating position in the talks leading up to the 1987 INF treaty provided a rationale for Moscow to withhold information on the SS-23s.

Washington insisted that the West German Pershing 1-A missiles could not be discussed or included in the agreement since the U.S.-made weapons were owned by the Bonn government. In response to Moscow’s insistence that the Pershings be destroyed, West Germany independently announced that the missiles would be eliminated. Nothing relating to those missiles was written into the treaty.

The Soviets have now claimed that they transferred the East German weapons outright in 1985 and therefore were not obligated to reveal the presence of the missiles outside their territory.

“The difference, of course, is that our transfer to West Germany was in the open, a public sale, while theirs to East Germany and the others was secret,” the official said.

The chronology of SS-23 disclosures, so far as known, is as follows:

East Germany announced last month that it had 24 SS-23s, after which the United States asked all the other Warsaw Pact nations “if they had SS-23 missiles on their territory,” a State Department official said. It also asked Moscow about the transfer.

Czechoslovakia replied that it had 72 missiles, which it described with dimensions but without giving the missile designation.

In its initial reply, Moscow apparently admitted that it transferred the weapons to East Germany in 1985 but apparently did not reveal information for the other transfers until after the Czechoslovaks said they had the missiles. The United States then told Moscow it was not satisfied with the initial response and broadened its question.

Only then, officials suggested, did the Soviets disclose transfers to Czechoslovakia and Bulgaria.