Defenders of the system counter that a book which fails to mention specific negative facts regarding the aggression and atrocities committed by Japan during World War II would also fail the Ministry of Education's approval process. During the approval process for the aforementioned history textbook by the Japanese Society for History Textbook Reform, the author was ordered to revise the book's content several times before receiving final approval. Moreover, during the Cold War, the Ministry rejected textbooks by left-leaning publishers which attempted to portray the Soviet Union, Mainland China, North Korea and other Communist countries in a positive light. Defenders also point out that during the 1960s and 1970s, the extent of the atrocities, as well as the existence of many of the incidents, were still being debated by Japanese historians; therefore, the Ministry of Education was correct in rejecting references to specific atrocities such as the Nanjing Massacre during that era, but the Ministry finally insisted on the inclusion of those same incidents after Japanese historians had finally reached consensus during the 1990s. They also point out that, North and South Korea, as well as China, which happen to be the most outspoken critics of the Japanese textbook approval process, do not allow private publishing companies to write history textbooks for their schools. Instead, the governments of those countries write a single history textbook for all of their schools. In the case of South Korea, the government strictly examines textbooks from different companies before being publicized. Critics of Chinese and Korean textbooks also argue that the textbooks of those countries are far more politically censored and self-favoring than Japanese textbooks.