China is the world's most populated country, and any country that tries to conquer it will end up assimilated instead(eg. the Mongols and the Manchus). However, by the late 19th century, the Qing Empire in China was on its last legs, and there was a fear that it may possibly have been partitioned and colonized by various imperial powers, namely the British Empire, Russia, and Japan. Because of this, the United States issued the "Open Door" notes, so that China would not fall to any nation that could cut off American trade. However, if the United States is too weak to issue and/or enforce the notes, such as after losing the ACW, would carving up and colonizing China be possible? Of course, with a POD decades earlier, China's decline isn't guaranteed, and it may possibly have been saved, but if China does fall to where it did IOTL, could Britain, Russia and Japan(and possibly France and Germany as well) have Chinese colonies(Hong Kong and Macau don't count)?