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PM Files

Memorandum by the Joint Chiefs of Staff to the Secretary of Defense (Johnson)

top secret
[Washington,] 23 November 1949.

Subject: The United States Military Position with Respect to the Development of the Thermonuclear Weapon.

The Joint Chiefs of Staff have studied the subject matter of this memorandum and have reached the following conclusions:

That the United States military position with respect to the development of the thermonuclear weapon should be:

a.
Possession of a thermonuclear weapon by the USSR without such possession by the United States would be intolerable.
b.
There is an imperative necessity of determining the feasibility of a thermonuclear explosion and its characteristics. Such determination is essential for U.S. defense planning, preparations for retaliation, and direction of research. It will have a profound effect on policy in the field of international affairs.
c.
If a thermonuclear weapon is determined to be feasible, the following additional considerations pertaining to military requirements are currently evident:
(1)
Possession of such weapons by the United States may act as a possible deterrent to war.
(2)
Possession of such weapon by the United States will provide an offensive weapon of the greatest known power possibilities thereby adding flexibility to our planning and to our operations in the event of hostilities.
d.
The cost in money, materials, and industrial effort of developing a thermonuclear weapon appears to be within the capabilities of the United States. Available information indicates that such a weapon may likewise be within the capability of the USSR.
e.
It is reasonable to anticipate, and in some cases it is known, that a number of thermonuclear weapons can substitute for a greater number of fission bombs. Further, the thermonuclear weapon promises in the high ranges of energy release to be more efficient in utilization of available ore and production capacity per unit area of damage.
f.
The foregoing considerations decisively outweigh the possible social, psychological and moral objections which may be considered to argue against research and development leading to a thermonuclear weapon by the United States.
g.
Any decisions or actions pertaining to the United States’ effort to develop a thermonuclear weapon or any determinations of its feasibility constitute a military secret of the highest classification. It should be possible to maintain secrecy on a subject of such importance to the security of the United States.
h.
A unilateral decision on the part of the United States not to develop a thermonuclear weapon will not prevent the development of such a weapon elsewhere.

For the Joint Chiefs of Staff:
Omar N. Bradley

Chairman Joint Chiefs of Staff