Foreign Relations of the United States, 1969–1976, Volume XXXII, SALT I, 1969–1972

289. Backchannel Message From the Chief of the Delegation to the Strategic Arms Limitation Talks (Smith) to the President’s Assistant for National Security Affairs (Kissinger)¹

Helsinki, May 21, 1972, 1727Z.

415. Dear Henry:

We tried yesterday the formulation on heavy missiles which you suggested. The Soviet side said that it was another variation of the same position which the Soviet Delegation had instructions to reject, and that it was therefore not acceptable.

We are continuing to explore further the concept of regarding as heavy all ICBMs “significantly larger” than the largest current light ICBMs, tied with a similar formulation on no significant increase in dimensions of ICBM silos. But it appears very unlikely that we will be able in this short time to move the Soviets from their position that no definition of “heavy” is needed. NSDM² instructions authorize fallback to unilateral statement on silo dimensions (depth and interior diameter), but do not authorize falling back to a unilateral statement on what we regard as constituting “heavy” ICBMs.

I believe the only feasible solution here, if we cannot get an acceptable agreed formulation, would be to make a unilateral statement; a suggested one is appended to this message.

I would appreciate appropriate urgent guidance on this point.³

Best regards,

Gerard C. Smith

Suggested unilateral statement:

The US Delegation regrets that the Soviet Delegation has not been prepared to agree on a mutually acceptable interpretive statement relating to Article II of the interim agreement. Rather than agree upon an inadequate statement, the United States now withdraws its proposal for an agreed interpretive statement relating to Article II. We note the repeated statements by the Soviet side that our concerns will be met by the terms of Article II under which the parties undertake not to convert land-based launchers for light ICBMs, or for ICBMs of older types deployed prior to 1964, and to land-based launchers for heavy ICBMs of types deployed after that time. The Soviet Delegation has repeatedly stated that there is a common understanding as to what constitutes a light ICBM, and as to what constitutes a heavy ICBM. The United States’understanding on this matter has been repeatedly communicated to the Soviet side. Under these circumstances, the US proceeds on the premise that the Soviet side will give due account to the US understanding.

1. Source: National Archives, Nixon Presidential Materials, NSC Files, Box 427, Backchannel Files, Backchannel Messages, 1972 SALT. Top Secret; Flash; Sensitive; Exclusive; Eyes Only. Haig initialed the message. Copies were sent to Howe and Odeen.
2. Reference is to NSDM 167, Document 279.
3. In backchannel message WH21470 to Smith, May 22, Kissinger replied, “You should persist in effort to set agreed formulation on heavy missiles. In any unilateral statement to which we might fall back you must include precise definition of what constitutes ‘US understanding.’” (National Archives, Nixon Presidential Materials, NSC Files, Box 427, Backchannel Files, Backchannel Messages, 1972 SALT)