REGULATION OF ARMAMENTS


79


    Even if not accepted it would possibly force the opponents Of an
  open world to explain their-reasons in public.
    For these reasons the Danish Government would view withgreat
  regret any statement from the American Government indicating
  dissociation from the thoughts expressed by Professor Bohr.
    WASHINGTON, June 21,1950.


  PM Files
  The Acting Chairman of the United State8 Atomic Energy Coin-
                mission (Pike) to the Secretary of State
  SECRET                                WASHINGTON, June 26, 1950.
    DEAR MR. ACHESON- The Commission and the General Advisory
  Committee to the Commission have had an opportunity to examine
  -the question raised in your letter of April 20, 1950, concerning the
  United Nations plan for the international control of atomic energy.
    We have examined the recommendations -of the United Nations
 Atomic Energy Commission, as embodied in Department of State
 Publication .3646. We have also examined in particular Part IV of
 the United Nations report, entitled "The First Report of the Atomic
 Energy Commission to the Security Council." This deals with the
 scientific and technical aspects of the problem of control, and makes
 explicit the agreed view of the technical problems which underlay the
 control plan.
   The Commission and the General Advisory Committee agree (1)
 that there have been no new scientific discoveries known to us which
 alter the situation; (2) that there maysoon be technical developments
 which have some bearing on control.-problems; and (3) that, with
 the passage, of time, major changes in the technical situation have
 occurred which profoundly alter the presuppositions under which
 the report appears to have been made. We may briefly summarize these
 points.
   1. No scientific discoveries are known to us which open up sources
of energy release not publicly known when the reports were written.
No discoveries lend support to the view that the large-scale release of
atomi energy can be based on raw materials other than uranium or
thorium.
  2. a. One technical development now underway in this.country may,
if successful, have an effect on the control plan. This is the electro-
nuclear generation of neutrons. If this turns out to be practical on a
large scale, it will mean that atomic energy can be released by con-
verting thorium to U-233 without the use of natural uranium. This
would mean that controls of thorium might have to be as strict as those
of uranium. This development would also make it possible to produce
not only U-233 but tritium and plutonium without the operation of