No worries Ian
It's no surprise that cutting-edge academic debates on Japanese history 400 years ago are beyond my ken. I'll bow out of that!
Toby's book looks comprehensive, but let's be honest, I'm never going to read it - lol.
I had a quick look at an extract - and I'm not sure what revelations it contains but it seems from the extract to support the idea that the country closed down trade with the outside world (apart from that one small port the Dutch had), which doesn't mean of course that it stopped paying attention to what was going on and remained sensitive to it for security reasons.
CHAPTER FOUR The World Through Binoculars: Bakufu Intelligence and Japanese Security in an Unstable East Asia REBUILDING Edo Castle in 1657 without the great tower of its central keep stood as fitting symbol of the bakufu's success in the domestic arena, and of its concomitant sense of security from any credible internal threat. Domestic affairs were, after all, reasonably within the sphere of shogunal competence, and they caused little concern to Edo for the next century and a half or more. Yet there remained beyond Japan's shores potential sources of danger that the bakufu could not keep directly under control, but only under careful scrutiny. The threat from Europe was effectively contained after the 1630s by the expulsion of the Iberians from the Japan trade, by the limitations placed on Japanese overseas travel, and by the restriction of Dutch access to Japan to the single port of Nagasaki. Danger from Japan's maritime and continental neighbors in East Asia, however, could not be so readily contained, nor could it be lightly dismissed. The massive physical size of China, and the geographic proximity ofJapan to the entire East Asian region, were simple facts of the Japanese environment, but in the seventeenth century the region was particularly volatile. This volatility was not only a result of the presence of the Europeans; massive civil wars in Japan, in the late sixteenth century, had spilled over into Asia, while international and civil wars in and around China were a virtual constant from the mid 1610s The World Through Binoculars — 111 to the mid 1680s. These wars the bakufu could not ignore, for they might at any time overflow the continent and wash upon the shores of Japan. They imposed upon the bakufu a continuously threatening international environment, which made Asian affairs, especially continental affairs, a source of constant security concern to the Edo authorities, for Japan inevitably became peripherally involved in these contests, either as a haven for refugees, or as a potential source of military assistance to one belligerent or another. Several times, indeed, the bakufu was forced to debate the question of whether to involve Japan directly in the conflict, either as a combatant, or as a supplier of arms and materiel. The answer to those questions was not consistently negative. For even though Japan has never been successfully invaded , in fully historical times, from the Asian mainland, nor subject to a dynasty of foreign conquest, at least after the sixth century,1 still, despite this high degree of apparent security, changes in the strategic balance in continental East Asia have often affected Japan in significant ways. Some modern scholars, for example, credit a perceived threat from the unifying Sui and T'ang dynasties in China, and the Silla unification of Korea, in the sixth and seventh centuries, with catalyzing the emergence of the first unified Japanese state.2 But more recent, and of much greater significance in the consciousness of the Japanese of Tokugawa times, were the thirteenth-century Mongol invasions of Japan, the only fully historic, and therefore clearly remembered, attempt by a foreign power to conquer Japan.3 1 See Gari K. Ledyard, "Galloping Along with the Horseriders, Looking for the Founders of Japan," in Journal ofJapanese Studies, 1.2 (Spring 1975): 217-254, for an illuminating discussion of the thesis that Japan was under a conquest dynasty in the fourth and fifth centuries. 2 It is the position of Inoue Mitsusada, for example, that, "Japan's direct motive in adopting the ritsuryo system [of Chinese-style centralized bureaucratic state] was the foreign rather than the domestic situation." See his "The Ritsuryo System in Japan," in Acta Asiatica, 31 (1977): 93. 3 For an introduction to the impact of the Mongol invasions of 1274 and 1281, see Kyotsu Hori, "The Economic and Political Effects of the Mongol 112 — The World Through Binoculars The rise of the Manchus to form a unified state, their struggle for control of China proper, and the final total victory of the Ch'ing dynasty (1644-1911) in the 1680s forcefully recalled for contemporary Japanese the Mongol invasions of four centuries earlier. The Manchu conquest of China forced Tokugawa Japan to remain sensitive to the shifting strategic balance in the region, to remain vigilant, and to be constantly aware of the fact that she could not avoid a strategic relationship to her environment. While perceived threats to the security of the Tokugawa state had led to increasingly stringent restrictions on European relations, and...