由于历史原因,中苏两国边界在黑龙江一段,在清朝时,只是简单地以江为界,没有严格划定。苏联一直站在当年沙俄蛮横的立场上,声称中国的边界应当划在界江界河的我方沿岸一线。这样一来,江中的岛屿(黑瞎子岛)自然就划归了苏联,而黑龙江和乌苏里江成了苏联的内河。……1969年,中苏两国的珍宝岛流血冲突,盖源于此。——摘自钱其琛回忆录《外交十记》 Due to historical reasons, the boundary between China and the Soviet Union was in Heilongjiang Section. In the Qing Dynasty, it was simply a river that was bounded on the river by no means. The Soviet Union has always stood in the brutal position of Tsarist Russia that year and claimed that the border of China should be drawn along the coastline of our border river. As a result, the island of the river (Black blind island) is naturally assigned to the Soviet Union, and Heilongjiang and the Ussuri River became the inland river of the Soviet Union. ... In 1969, there was a bloody clash of treasure island between China and the Soviet Union. - From Qian Qichen memoir “Diplomatic Ten Notes”