And then at last it came. It came as a surprise to all the world because its real causes were hidden. Relations were strained between Germany and the United States because of the intense exasperation of a tariff conflict and the ambiguous attitude of the former power towards the Monroe Doctrine, and they were strained between the United States and Japan because of the perennial citizenship question. But in both cases these were standing causes of offence. The real deciding cause, it is now known, was the perfecting of the Pforzheim engine by Germany and the consequent possibility of a rapid and entirely practicable airship. At that time Germany was by far the most efficient power in the world, better organised for swift and secret action, better equipped with the resources of modern science, and with her official and administrative classes at a higher level of education and training. These things she knew, and she exaggerated that knowledge to the pitch of contempt for the secret counsels of her neighbours. It may be that with the habit of self-confidence her spying upon them had grown less thorough. Moreover, she had a tradition of unsentimental and unscrupulous action that vitiated her international outlook profoundly. With the coming of these new weapons her collective intelligence thrilled with the sense that now her moment had come. Once again in the history of progress it seemed she held the decisive weapon. Now she might strike and conquer--before the others had anything but experiments in the air. Particularly she must strike America, swiftly, because there, if anywhere, lay the chance of an aerial rival. It was known that America possessed a flying-machine of considerable practical value, developed out of the Wright model; but it was not supposed that the Washington War Office had made any wholesale attempts to create an aerial navy. It was necessary to strike before they could do so. France had a fleet of slow navigables, several dating from 1908, that could make no possible headway against the new type. They had been built solely for reconnoitring purposes on the eastern frontier, they were mostly too small to carry more than a couple of dozen men without arms or provisions, and not one could do forty miles an hour. Great Britain, it seemed, in an access of meanness, temporised and wrangled with the imperial spirited Butteridge and his extraordinary invention. That also was not in play--and could not be for some months at the earliest. From Asia there came no sign. The Germans explained this by saying the yellow peoples were without invention. No other competitor was worth considering. “Now or never,” said the Germans--“now or never we may seize the air--as once the British seized the seas! While all the other powers are still experimenting.”