Throughout its modern history, Japan offers a unique example of extreme national consciousness combined with exceptional sensitivity to the outside world--one or another part, significantly, at one or another time. Here, in the 1975 Brown & Haley lectures at the University of Puget Sound (updated to account for recent developments and publications), Princeton historian Jansen, a leader in Japanese studies, briefly examines changing Japanese perceptions of other nations through the careers and views of key figures who, in old age, wrote their memoirs. In 1771, after 140 years of Japanese seclusion, doctor Sugita Gempaku witnessed the dissection of an executed criminal; when he discovered that the Chinese medical textbooks were wrong and a Dutch anatomy he'd acquired was right, Sugita undertook, with a colleague, to translate the Dutch work--touching off an era of translation of Western books that expanded into an assault on the Chinese cultural tradition. . . already under attack by literary ideologues of Japanism. (Jansen is always careful not to construe a symbolic event as the sole cause.) In 1871-73, after Perry ""opened"" Japan, Kume Kunitake accompanied the great governmental learning expedition around the world; the Japanese had much to learn, he reported, but there was a choice of what to learn from where and no immediate danger of falling, like China, under Western domination; Japan could proceed to modernize slowly, for its own benefit--meanwhile, as Kume later wrote, watching materialistic Britain ""begin to decline."" For Japan's 20th century outlook, Jansen has no such well-placed memoirist (yet), nor so clear a pattern of rankings. Japan counted now; the rest of the world, after World War I, was in disarray. Nationalist China was weak; totalitarian states loomed in Europe. The Japanese courtship of the major maritime powers, Britain and the US, was no safeguard against racism (at Versailles, in the 1924 US immigration legislation, at the arms-limitation conferences). ""A strong Japan might well reconsider its stance and strike out for regional domination."" There was, Jansen points out, no consensus; but rather a drift--to a war seen as preferable to inaction. It's a cogent, thoughtful analysis--extended into an assessment of Japan's international role today--that provides an excellent grounding for students and a stimulating review for specialists.