Axis Reactions to Use of Cocos Islands as a Staging Point Report by J.I.C.

If and when the Japanese first appreciate that the Cocos Islands are being developed as a base they may attempt to bombard with cruisers and destroyers, using submarines to warn them of the approach of superior Allied naval forces, and relying on their speed and the short distance to the Sunda Straits to make up for the absence of fighter cover. In any case they would choose an opportunity when they considered that the Allied naval forces in the waters concerned were not superior to their own. Whether or not they actually succeed in bombarding, they will certainly attack any inadequately pretected shipping in neighbouring waters, probably by torpedo, since the Japanese cruisers have been concentrating on the use of large numbers of heavy long range torpedoes.