Z Committee

The Z Committee was a three-member National Security Council committee created to advise Harry S. Truman on whether the United States should develop a hydrogen bomb and whether the issue should be made public. Its two meetings became a forum for a sharp dispute over Soviet capabilities, the danger of delay, and the costs and consequences of a new arms race; the committee ultimately recommended proceeding, despite David E. Lilienthal’s reservations.

Formation and Mandate

The committee was appointed on November 10, 1949, the day after an advisory committee unanimously recommended against developing the superbomb and the Atomic Energy Commission also advised against it. The commission had reached its decision by a 3–2 vote, with Lilienthal casting the deciding vote. Truman named Dean Acheson, Louis Johnson, and Lilienthal to advise him both on whether to proceed and on whether the matter should receive publicity.

The question did not remain secret for long. A week after the committee’s appointment, Washington knew that the superbomb was under consideration. The first hint reached a Washington Post reporter after a Colorado senator discussed the issue on local television while expressing concern about scientists’ ability to keep secrets. The committee’s work therefore unfolded alongside a growing public debate, even as its own discussions were meant to be restricted.

A Divided Deliberation

The top-secret debate lasted three months, from November 1949 through the end of January 1950. Much of it took place in Dean Acheson’s large fifth-floor office at the United States Department of State. The three members met only twice, on December 22 and January 31; Acheson attributed the sparse meetings primarily to the bitter relationship between Johnson and Lilienthal.

By the final session, the disagreement had sharpened. The Joint Chiefs of Staff wanted a crash program, and Johnson supported moving ahead. Lilienthal warned against making the decision in an atmosphere of excitement: beginning work could close off a new approach to the atomic arms race, entrench reliance on a single kind of weapon, distort defense budgets and foreign policy, and give the public a false sense that the balance of power would belong to the United States. Acheson admired Lilienthal’s objections but judged that two realities outweighed them: delaying American work would not delay Soviet work, and the American public would not accept a policy of waiting.

The Final Meeting and Recommendation

On January 31, 1950, the members convened for their final session in Room 216 of the Old State Department Building. Acheson took charge of the discussion, argued that work should proceed, and brought forward a draft statement for Truman. Johnson agreed. Lilienthal still had grave reservations, but agreed to sign the statement after Johnson said, “We must protect the President.” The recommendation thus reflected agreement on the course to present, not a disappearance of the committee’s substantive disagreement.

The three members then walked to the White House with an executive secretary of the National Security Council. Their own meeting had lasted two and a half hours; their meeting with Truman took seven minutes. Lilienthal later wrote that the President seemed to have settled on his decision before the group arrived, perhaps as much as ten days earlier. The committee therefore advised on a choice Truman may already have made, rather than resolving the question for him.

Significance

The Z Committee’s record captures a policy decision taking shape through a compressed, uneven process: an initial recommendation against development, only two meetings among sharply divided members, and a final statement supporting work on the weapon. Its brief consultation exposed the limits of consensus within the administration. Lilienthal’s signature helped present a unified recommendation, but his objections remained part of the deliberation; Acheson’s case for proceeding rested on the expectation of Soviet development and the political unacceptability of delay.