Original sentence: The Treaty of Ganghwa became the first unequal treaty signed between Korea and foreign country; it gave extraterritorial rights to Japanese citizens in Korea, forced the Korean government to open three ports to Japanese and foreign trade, Busan, Incheon and Wonsan
Edited sentence: Korea had until this point paid regular tribute to China, Korean kings first had to be approved by China, and at various times Korea considered itself culturally descended from China, although China would customarily reciprocate to these tributes with gifts of equal value and the Chinese generally rubber-stamped any candidate proposed for king in Korea.Nevertheless, by driving a political wedge, whether perceived or real, between Korea and China, Japan effectively made it more difficult for Korea to seek Chinese military assistance.The Treaty of Ganghwa became the first unequal treaty signed by Korea; it gave extraterritorial rights to Japanese citizens in Korea, forced the Korean government to open three ports to Japanese and foreign trade, Busan, Incheon and Wonsan, and established Korean independence from China.Thus establishing independence was to some extent just political phrasing