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The present situation cannot, however, be regarded as permanent. Should the Anglo-Japanese Treaty be determined, not only would it no longer be possible to assume that the Japanese fleet would act in concert with the British navy in time of war, but the possibility of Japan being ranged against us, either alone or in combination with some other naval Power, cannot prudently be disregarded.

11. The strategic position of Canada and the nature and scale of the overland attacks that the local defences might be called upon to sustain in the event of a war with Japan therefore require special consideration.

It must be assumed that, at the outbreak of hostilities, the local command of the Pacific might for a brief period rest with Japan, until such time as British naval reinforcements could arrive from European waters. During that period it would no doubt be possible for Japan to convey oversea to Canada a military force of considerable size.

12. In considering the scale and nature of oversea attack that the temporary possession of the local command of the Pacific would enable Japan to bring to bear on Canadian territory, it is, however, necessary to draw a clear distinction between large operations, the success of which will depend upon the power of the Japanese fleet to keep open oversea communications with its bases for an indefinite period, and hasty raids dependent for success rather upon surprise and rapidity of execution than upon the number of troops employed.

13. The oversea conveyance from a distant base of operations of a military expedition strong enough to effect a prolonged or permanent occupation of any considerable area of British territory, and the continued supply of such an expedi- tionary force when landed with munitions of war, would be possible only to a Power which was mistress of the seas and was able to destroy or mask all the hostile ships that might at any time be in a position to interrupt the communications of the expeditionary force.

No such oversea expedition has ever been carried to a successful conclusion unless this condition has been fulfilled, and some of the greatest military disasters recorded in history have resulted from failure to secure or retain the assured sea command which is essential for the prosecution of an oversea campaign.

14. It is thus evident that so long as British naval strength is calculated and maintained on the basis of securing command of the sea against all probable enemies the nature and scale of the oversea attacks to which the Pacific Coast of Canada will be exposed, even during the period that local command of the sea temporarily rests with the enemy, will be subject to definite limitations.

The size of the oversea expeditionary force that Japan could bring against Canada will be limited by the condition that there must be a reasonable probability that any enterprise undertaken could be brought to a successful conclusion before a British fleet could intervene.

15. Apart from the fact that diplomatic considerations would probably deter Japan from incurring the risk of embroiling herself with the United States by undertaking military operations on the American Continent, it is only reasonable to assume that Japan would utilise the opportunities that would be conferred upon her by the temporary possession of local command of the sea in such a way as to inflict the maximum of injury upon us with the minimum of risk to her own naval and military forces.

It is not possible to forecast with certainty the action of the enemy in war, but it may confidently be predicted that any opportunities of oversea action that may be offered to Japan in the early stages of a war through the temporary possession of the command of the Pacific would not be utilised by her to undertake serious operations on the Pacific Coast of Canada-4,000 miles distant from Japanese naval bases-from which she could not hope to achieve any permanent successes.

16. Having regard to these considerations, the Admiralty are of opinion that, so long as the British fleet remains capable of acting on the offensive, it is not reasonably probable that any attack on the Canadian coast more formidable than a raid by one or two unarmoured cruisers will be undertaken.

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