Such a ground for war was only a means for mobilizing the widest sections of democracy.
America could not possibly wage an unpopular war. Bismarck said very beautifully in his letter addressed to Salisbury, to which I have referred above, that no matter who was Kaiser and no matter what the Kaiser wished, it was impossible to mobilize the millions of Germans if the nation did not comprehend the causes of war and did not approve them. This applies undoubtedly to America much more than to Germany.
With the U-boat war we furnished an ideal casus belli to America. The self-consciousness of America was offended because her threats were disregarded. In view of her highly developed trade, America considered her interests endangered by the U-boat war. The killing of women and children also offended American sentiment. The disregard of international law, moreover, furnished the military party with a powerful weapon against the Central Powers. And finally, if there had been a possibility of preserving peace, this possibility vanished in consequence of the fact that the plan was made public that the German Government had intended to ally herself against America, with Mexico and Japan. Germany had determined to make an ally of Mexico, which was the object of the deepest hatred and the most bitter contempt in America.
When I was in Berlin in the summer of 1916, I had an opportunity of discussing this question with several leading politicians. The Chancellor gave strength to my conviction that the use of the U-boat war was a
