ANNEX '2
 
PROBABLE MAXIMUM :SCALE OF ENEMY ATTACK ON WEST
 
COAST OF NORTH AMERICA
 
EXAMINATION OF PROBABLE FORM OF ENEMY ATTACK.
 
         1, Enemy attack on the western seaboard of North America might
be undertaken with the' object of reducing United States offensive
power in the Pacific through material destruction at shipyards and
bases and alsowith the object of containing forces in America.
 
         2.        The following forms of attack have been considered-
-
 
                    .a, Seaborne expeditions;
 
                    b. Naval bombardment;
 
Carr. ier-borne air attacks;
 
             d, Mine-laying in ports and their approaches and attacks
by human torpedoes.
 
SEABORNE EXPEDITIONS.
 
         3. So long as a United States capital ship force is retained
in the Pacific~ .it is extremely improbable that the Japanese would
venture to launch a large scale expedition against a North Amer. ican
objective without battleship cover. ~it must also be assumed that apart
from the destroyer escorts for the co~voys~ destroyers would be
essential for A/A and A/S protectionfor the battleships.
 
       4    The diagram attached':: to this Annex illustrates the large
distances to be covered and shows that even if the enemy secured Dutch
Harbour and 'Hawaii,, it would be necessary to carry out the refuelin~
of destroyers at sea~
 
                 While the refueling of an expedit'ion at sea in
'hostile waters can not be ruled out positively, the complications and
risks of such an operation on a large scale are sufficiently great to
make .it extremely unlikely. Added to this factor is the problem of
maintaining a large scale expedition over 4~000 miles from its base.
 
z .' APPENDIX A
 
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