U.S. nuclear weapons strategy evolved during the Nixon administration from a reflexive policy of massive retaliation against a Soviet attack to a diverse range of options for more limited nuclear strikes. The transition was not without some bumps.

A declassified 1974 memo recorded that National Security Adviser Henry Kissinger at first needed some persuading about the efficacy of limited strikes.

Kissinger “expressed concern that many of the options appeared to him as too timid. He judged that nuclear use must have a decisive military effect in order to achieve the desired political goal– convince enemy to stop.”

“Too mild a nuclear option is likely to convince the enemy to persevere, or respond tit for tat, or both,” Kissinger said, as paraphrased in the 1974 Pentagon memo.

The formerly Top Secret memo (document 36) is one of many that appeared in a richly informative, 1,000-page new volume of the State Department’s Foreign Relations of the United States (FRUS) series on National Security Policy, 1973-1976 that was released this week.

Kissinger was soon convinced of the need for greater flexibility, and presented the argument himself to President Nixon.

“The concept that we could ‘win’ a war through virtually unlimited nuclear exchanges has become increasingly irrational as the Soviets acquired the capability to destroy the United States– even if the U.S. were to strike first,” he wrote in a memorandum to the President (document 30). “This has resulted in concern that such a strategy is no longer credible and that it detracts from our overall deterrent.”

The proposed new nuclear policy would therefore provide “for the development of a broad range of limited options aimed at terminating war on terms acceptable to the U.S. at the lowest level of conflict feasible.” Still, it would preserve “the major SIOP-type options in the event that escalation cannot be controlled.”

Kissinger asked President Nixon to approve the proposed steps and “authorize me to sign” the new nuclear weapons policy. Nixon did approve, but he wrote that “RN will sign.”

The FRUS volume is full of impressive, candid and chatty source documents on the diverse national security issues of the time, including anti-satellite weapons, the notorious “Team B” competitive analysis project that challenged CIA assessments of Soviet military strength, the Glomar Explorer effort to raise a sunken Soviet submarine, and the growing threat of Soviet surveillance and interception of U.S. communications.

The fear that Soviets were monitoring U.S. telephone communications inspired a concerted effort to improve communications security against espionage and the invasion of privacy.

“The President… recognizes that U.S. citizens and institutions should have a reasonable expectation of privacy from foreign or domestic intercept when using the public telephone system,” according to National Security Decision Memorandum 338 of September 1, 1976 (document 180).

The Foreign Relations of the United States series has been an important driver of the declassification process, identifying high-value historical records for declassification review. While it sometimes represents the state of the art in declassification, other times it lags behind, probably due to the painfully slow pace of the review and production process. (The latest volume was under declassification review from 2007 to 2014.)

In some peculiar cases, FRUS both leads and lags in declassification. So, for example, the new FRUS volume includes a copy of the 1976 National Security Decision Memorandum 333 on “Enhanced Survivability of Critical U.S. Military and Intelligence Space Systems” (document 91). The newly published document includes two declassified paragraphs that had been withheld from public release as recently as 2008. Incongruously, however, the new FRUS version of NSDM 333 also withholds two lines concerning threats against U.S. satellites that it mistakenly says were “not declassified.” In fact, those lines were declassified years ago in the NSDM 333 that is available from the Ford Presidential Library. The two contrasting and complementary versions of NSDM 333 can be viewed here and here.