“Environmental degradation resulting from trade in Ezo [old name of Hokkaido] cautions against the argument that commercial growth in early-modern Japan was confined to, as some suggest, a “total environment”. In the Tokugawa years, the Japanese did not set their collective sights exclusively on resources that lay within the traditional provinces or confine themselves to a “total environment,” but rather cast their gaze widely over Hokkaido, the Kuril Islands, and much of Sakhalin Island, searching for new resources to fuel the flames of markget growth, to fertilize cash crops, and to feed a stable urban population. In this way, even in early-modern Japan, the environmental context was not fixed but was, as Conrad Totman insists, “shaping and beaing shaped by human activities.” Environmental changes were “crucial variables in the Tokugawa economic experience.” This economic expansion into Ezo, in addition to having implications for Ainu and other groups in the North Pacific, raises intriguing questions concerning whether Japanese colonialism in East Asia should be viewed as an exclusively post-Meiji phenomenon, or in other words, as the imperialist implications of modernization shaped predominantly by Western models. To begin with, in the realm of what Alfred Crosby calls “ecological imperialism,” the exchange of contagions in Ezo and the demographic and cultural consequences of massive epidemics introduce the horrible specter of the interactions between semi-insular populations such as the Ainu and endemic-disease carriers such as the Japanese. Of all the many facets of the Ainu-Japanese relations […] disease clearted the way for the Japanese settlement of Hokkaido possibly more than any other factor and, hence, pushes historians to confront the ecological implications of expansion in Japan’s pre-Meiji world. On a political leve, moreover, the link between the state, merchants and foreign conquest in Ezo resembles the later Japanese colonial experience in Korea, where, as Peter Duus argues, the “symbiotic ties” formed between government and business facilitated the national enterprise of the annexation of Korea. The political process of colonizing Korea, writes Duus, was associated with the “penetration of the Korean market by an anonymous army of Japanese traders, sojourners, and settlers,” resembling with important distinctions, the situation in Ezo.”

— Brett L Walker, The Conquest of Ainu Lands: Ecology and Culture in Japanese Expansion 1590-1800