It will readily be comprehended that these recommendations, had they been adopted, would at the outset have involved such sweeping reforms in the methods of administration as would have procured for Sakuma in any case a whole host of enemies, for there were vested interests to be considered in those times as in every age, and it is not at all surprising to learn that his proposals were not received with any degree of favour: admirable as they were in conception, they struck at the very root of the system on which the Tokugawa rule was based, after the closing of the country to foreign intercourse in 1638, which was that of complete seclusion from the rest of the world, and the memorandum was, as might be said, pigeon-holed for future reference. To fully appreciate the risk that Sakuma ran in putting forward proposals so entirely subversive of the existing order of things, it must be brought to mind for an instant that early in the seventeenth century of the Christian era, at a time when the over-sea trade of Japan had attained to some importance, the Tokugawa Government sternly suppressed all trade with foreign nations on account of the attempts of the Jesuit missionaries, it was said, to obtain for their order that political influence in Japan that they had succeeded in securing at the time in China. The construction of large vessels was prohibited under very severe penalties, and a maritime trade that bade fair to prove eminently advantageous to Japan was strangled at the outset. As far as can be gleaned from the records of that period, Japan had in 1620 about 200 ocean-going ships, fit to brave the storms that were usually to be encountered in the course of a voyage to India, Mexico, or the islands of the South Seas, where the Japanese flag was in those days by no means rarely to be seen. The order that thenceforward Japanese ships were to have but one mast struck at the root of naval expansion, and Japan was still suffering the consequences of this drastic regulation when Sakuma penned his remarkable essay on needed measures of defence.