You know how ready I am to discuss important matters with you, but _ultra posse nemo tenetur_--it was physically impossible to upset everything again and to expect His Majesty to alter his views. In true friendship, your CZERNIN. I thereupon, on March 14, received the following answer from Tisza: DEAR FRIEND,--I also note with genuine pleasure the success of your American _aide-memoire_ (meaning thereby America's resolve not to break off relations with us). But it does not alter my opinion that it was a pity to admit that a pledge had been given. It may be requited at a later stage of the controversy, and it would have been easy not to broach the subject for the moment. Do you think me very obstinate? I have not suppressed the final word in our retrospective controversy so that you should not think me better than I am. Au revoir, in true friendship, your TISZA. Tisza was strongly opposed to the U-boat warfare, and only tolerated it from reasons of _vis major_, because we could not prevent the German military leaders from adopting the measure, and because he, and I too, were convinced that "not joining in" would have been of no advantage to us. Not until very much later--in fact, not until after the war--did I learn from a reliable source that Germany, with an incomprehensible misunderstanding of the situation, had restricted the building of more U-boats during the war. The Secretary of State, Capelle, was approached by competent naval technical experts, who told him that, by stopping the building of all other vessels, a fivefold number of U-boats could be built. Capelle rejected the proposal on the pretext "that nobody would know what to do with so many U-boats when the war was at an end." Germany had, as mentioned, 100 submarines; had she possessed 500, she might have achieved her aims. I only heard this in the winter of 1918, but it was from a source from which I invariably gleaned correct information.