IF there were one main theme to Japanese history, it might be described as the challenge a small island nation faces to maintain its distinctive identity while still borrowing and adapting endlessly - words, political ideas, technologies - from neighbors around the world. The Japanese have a marked introspective concern with what it means to be Japanese even as they wonder how to define their ``place in the world.'' Their commendable willingness to learn from others, despite a strong sense of national identity, sets the Japanese apart from the Chinese, for instance, whose sense of being at the center of the universe has left them largely uninterested in other countries.
But Japan has come only slowly to a more active role on the international stage - not without reason. In the aftermath of World War II there was every desire to prevent the rearmament of Japan. Now that the concerns of Western allies have shifted to the Soviet bloc instead, they might wish to have Japan assume more of the costs of defending itself and its Pacific neighbors. But the Japanese politely say, no, thank you, and continue quietly along with military spending at only a hair above 1 percent of their gross national product - a fraction of the proportion of GNP other nations devote to defense.
More recently the Japanese have moved into a new role as foreign-aid superpower. Last week the Cabinet in Tokyo approved a five-year, $50 billion aid program expected to make Japan the world's leading foreign-aid donor. It's not a role that Japan has come to without some nudging, however. For one thing, Japanese foreign aid has seemed intended to benefit Japanese business interests - construction companies, for instance - more than needy people abroad.
And Japanese tend to be braced for not being liked. The rice subsidy and other programs intended to keep Japan self-sufficient in food production are maintained in part because of concern that in another war, Japan would have no allies willing to sell it food.
But curiously, Japan often seems unwilling to requite affection. The annals of Japanology are strewn with Westerners who have broken their picks trying to be truly accepted by the Japanese, from Lafcadio Hearn, the turn-of-the-century interpreter of Japan to the West, to a more recent writer, Alan Booth. His ``The Roads to Sata,'' an account of his walk from one end of the country to the other, ends with someone's telling him bluntly, ``You can't understand Japan.''
Meanwhile, the Japanese go on making their selective borrowings and continuing their study of English - taking care not to learn so much that their Japanese-ness is endangered. But a distinctive identity, like happiness, is better achieved as a byproduct than as a principal goal in itself: This may be the lesson the Japanese must learn.
Last in a series.