Z38            FOREIGN RELATIONS, 19 5 0, VOLUME I
amount of contribution cannot now be indicated in the absence of
knowledge as to the size of program Belgium may contemplate.
   British here concur in all foregoing, subject:
   (a) minor amendments to communique not affecting substance, and
   (b) confirmation Foreign Office which will be passed British Am-
 bassador Brussels.
                                                         AcHE SON
PM Files
M/emnorandum by the Executive Secretary of the National Security
                          Coun'cil (Lay)
TOP SECRET                            WASHINGTON, M\1arch 1, 1950.
Memorandum for: The Secretary of State
                    The Secretary of Defense
                    The Chairman, Atomic Energy Commission
Subject: Development of Thermonuclear Weapons
  At the direction of the President the enclosed letter from the Sec-
retary of Defense on the subject is referred herewith to the above
Special Committee of the National Security Council for submission
to the President of advice regarding the recommendation contained
in the last paragraph -hereof.
  In accordance with the Committee's normal procedure, representa-
tives of each of the members have initiated the urgent preparation of
a staff study of this proposed program. with particular reference to
its feasibility, for consideration by the Committee as a basis for its
advice to the President.
                                               JAmEs S. LAY, JR.

                             [Annex]
        The Secretary of Defense (Johnson) to the President

TOP SECRET                         WASHINGTON, 24 February- 1950.
  DEAR MR. PRESIDENT: Since your recent decision with respect to
work by the Atomic Energy Commission on the hydrogen bomb, cer-
tain developments, which you and I have discussed, make it 'apparent
-that the Soviets may already have made hnportant progress in this
field of atomic weapons.'
  In view of the extremely serious, in fat almost literally limitless,
implications to our national-security if the 'above conclusion should
prove to be factual, I have requested the Joint Chiefs of St:aff .to give

* "No record of a Truman-Johnson conversation on this subject has been
found
in the files of the Department of State. The developments referred to by
Secre-
tary Johnson related to the Fuchs case. Further information on the origins
of
this communication appears in H~ewlett and Duncan, pp. 415-416.