qualify their statements with—“for the present.” They seem to believe that it will come to submarines or submersibles in the end.
We all know from the expression of the late war how perfectly the ocean protects submarines. Germans have told me since the Armistice that at no time did the Imperial Navy have more than fifty of these craft cruising at once; usually there were only about twenty-five. Against them, the Allies were using at least half of their naval resources; thousands of craft, from giant dreadnoughts to swift little chasers, mobilized to fight imperfectly less than fifty of these deep-sea assassins! You can attack them with other naval vessels only from the surface. That “submarine cannot fight submarine” is a naval axiom. In the next war, a few hundred submersibles of the new, swift, powerful type could almost undoubtedly accomplish what Germany failed to accomplish in 1917 and 1918—establish an effective food-blockade of England or of any other region dependent upon overseas importation for its bread and meat.
And whoever starts such a campaign will unquestionably heed the plea of “national necessity” as did Germany in 1917–1918: abrogate the old sea-law which compelled attackers to warn ships about to be sunk, and strike out of the darkness and the sea-depths. For the lid is off.
So we may add to the possible death-cost in the
