718.5/11–2054
The Under Secretary of State (Hoover) to the Secretary of Defense (Wilson)1
My Dear Mr. Secretary: On August 4, 1954, Assistant Secretary Henry F. Holland addressed a letter2 to the Secretary of the Army requesting that advance planning be carried out concerning the nature [Page 861] of military action which might be necessary to assist in the defense of Costa Rica in the event that the Government of Costa Rica should request such assistance under Article 3 of the Rio Treaty. A copy of the letter of August 4 is enclosed3 for your convenient reference.
The Department of State has received continuing reports of the possibility that Costa Rica might be subjected to such an attack. Although the probability of such an attack is very difficult to estimate and may not be great, it does appear probable that if such an attack should occur it would involve the use of aircraft, since the potential attackers are believed to have been impressed with the effective use of aircraft in the recent revolution in Guatemala. Since the Government of Costa Rica possesses no military aircraft, such an attack would probably be clearly identifiable as coming from outside the territory of Costa Rica.
As stated in the letter of August 4, United States armed forces would be used to defend Costa Rica only upon authorization of the President of the United States after the evaluation of a direct attack. I believe the present circumstances are such that it would be advisable to have a small number of intercepter aircraft, possibly six airplanes, based in as close proximity to Costa Rica as practicable. If these aircraft were in the Canal Zone, they would be less than an hour away from Costa Rica. The movement of these aircraft to the Canal Zone might, in itself, if it were permitted to be known discreetly to the potential attackers, have the effect of deterring an attack. As a part of, or supplement to, the existing planning operation, the Department of State would appreciate this precautionary action. The Department of State would arrange for the discreet mention of this action to persons who are believed to be in touch with the potential attackers.
Sincerely yours,