In the aftermath of the Opium War of 1839–42, China was continuously subjected to increasing Western political and economic penetration. The Treaty of Nanjing was only the first of a series of unequal treaties which led to the opening of over 100 treaty ports along the coast and in the interior of China. In many of these ports Great Britain, France, Germany, Russia, the United States, Japan and other imperialist powers set up concessions under their administration and outside Chinese jurisdiction. There their nationals could freely trade, invest in banking, industry and construction, and engage in missionary and other cultural activities. Thus, although China never completely fell under the direct control of any imperialist power, the treaty ports were functionally similar to the port cities of Western colonies as linkages to the metropolitan countries.Did these treaty ports serve as beachheads of imperialism which facilitated foreign extraction of raw materials, exploitation of a cheap labor market, and displacement by cheap imports of native handicrafts left unprotected by the loss of tariff autonomy, as neo-Marxist historians charge? Or, as the revisionist scholars contend, were they centers of political and economic modernization where Western ideas and institutions were communicated to the Chinese, and where Western entrepreneurship and capital not only pioneered in modern industry, but also prompted imitative responsesfrom Chinese entrepreneurs? And yet, did the ports fail to have any major impact at all on Chinese political organization and socio-economic development, as Chinese mercantile interests thwarted Western attempts to penetrate the economy?