to be attacked therein if the enemy is to succeed against us as well as against the European Entente.
The number of available enemy submarines is not unlimited, and the difficulties of obtaining and maintaining bases are fully as difficult for submarine as for surface craft.
The difficulties experienced by enemy submarines en route and in operating as far from their bases as they now do are prodigious.
Operations on our coast without a base are impracticable, except by very limited numbers for brief periods, purely as diversions.
In view of our distance from enemy home bases, the extent of our coastline, and the distances between our principal ports, it is a safe assumption that if we could induce the enemy to shift the submarine war area to our coasts his defeat would be assured, and his present success would be diminished more than in proportion to the number of submarines he diverted from the more accessible area where commerce necessarily focuses. 14. The Department's policy refers to willingness to extend hearty co-operation to the Allies, and to discuss plans for joint operations, and also to its readiness to consider any plans which may be submitted by the joint Allied Admiralties.
15. I submit that it is impossible to carry out this co-operation, to discuss plans with the various Admiralties, except in one way and that is, to establish what might be termed an advance headquarters in the war zone composed of Department representatives upon whose recommendations the Department can depend.
I refer to exactly the same procedure as is now carried out in the army that is, the General Headquarters in the field being the advance headquarters of the War Department at home, and the advance headquarters must of necessity be left a certain area of discretion and freedom of action as concerns the details of the measures necessitated by the military situations as they arise.
16. The time element is one of the most vital of all elements which enter into military warfare, and hence delays in communications by written reports, together with the necessity for secrecy, render it very difficult to discuss plans at long range. The enemy secret service has proved itself to be of extraordinary efficiency.
Moreover, I believe it to be very unsafe to depend upon discussion of military plans by cable, as well as by letter. The necessary inadequacy of written or cable communications needs no discussion. The opportunities for misunderstandings are great. It is difficult to be sure that one has expressed clearly one's meaning in writing, and hence phrases in a letter
