Memorandum From the Joint Chiefs of Staff for President Roosevelt12a

The Joint Chiefs of Staff have considered the military aspects of the acquisition of air and naval bases in Ireland.
Air transport and air ferry operations will not be materially improved by acquiring such bases. Air operations by very long range aircraft for the protection of shipping would not be appreciable [appreciably] extended in range. In both instances, however, an additional degree of safety and flexibility would be had through the availability of additional fields.
Air operations against the European Continent would not be appreciable [appreciably] facilitated by use of bases in Eire except that bases for fighter planes in southwest Eire would be of advantage to the theater commander as bases to which he might move his fighter planes to oppose German air attacks on Allied convoys if they should be routed south of Ireland.
This air threat together with that of the German submarines operating from bases in western France are now deterrent factors in the routing of seaborne traffic to England through lanes south of Ireland. Air bases will reduce the air threat but naval bases will not materially reduce the existent submarine threat because present bases in southwest England are closer to the Bay of Biscay. However, naval bases will be useful when it is considered safe enough to route convoys south of Ireland and when invasion operations start in western Europe. They can be quickly established with floating equipment.
The Joint Chiefs of Staff consider that fighter air bases and naval bases in southern Eire will be strategically valuable to the United Nations when shipping is routed past southern Ireland or when an invasion of western Europe is undertaken.
A saving of American lives and the lives of nationals of those countries associated with us in the war, might result from availability of suitable emergency landing fields in Eire, and would result from availability of air and naval bases when it becomes feasible to route convoys south of Ireland.
It is recommended that negotiations be conducted without committing the U.S. at this time to a definite program for the establishment of air or naval bases in southern Ireland.
A copy of this memorandum is being sent to the Secretary of State, and officers representing the Joint Chiefs of Staff have been designated to consult with him in this matter.
For the Joint Chiefs of Staff:
[George C. Marshall]

Chief of Staff, U.S. Army.
  1. Copy obtained from the Joint Chiefs of Staff.