Among 47 new inscriptions, UNESCO added documents of the Nanjing Massacre to the Memory of the World Register on Friday. International recognition of the documentary heritage that testifies to the atrocities committed in the city is an important part of international efforts to preserve the collective memory of mankind and promote peace and justice.

Given the repeated denials and whitewashing of their country's past by Japanese nationalists, UNESCO's inclusion of the materials as part of the world's memory is an authoritative international refusal to condone the lies of Japanese far-rightists. From now on, any denial of the massacre is futile.

As a country that has yet to sincerely own up to its history of aggression in World War II, Japan tried to block the UNESCO move. Japan's foreign ministry said it was "extremely regrettable" and questioned the world body's neutrality and fairness, and even called for the process to be reformed.

Such comments are based on neither fact nor reason, as both the iron-clad historical facts about the massacre and UNESCO's process of nomination and inscription are beyond question.

The Japanese far-rightists can try and deny the facts all they want, but now the rest of the world has a clearer picture of what really happened in the Chinese capital at that time, when the invading Japanese army killed 300,000 civilians and unarmed combatants over the course of six weeks.

The event, often referred to as the "Rape of Nanking", was reported worldwide, witnessed by journalists from Western media including the New York Times, the Associated Press and the Chicago Daily News. No respected historians and mainstream academics in the world doubt that the massacre took place.

As to the UNESCO decision, it was made following a two-year process as part of the 2014-2015 nomination cycle during which 88 submissions from 61 countries were examined. The Japanese accusation is a desperate attempt to discredit its decision.

If Japan still deems itself as a responsible member of UNESCO, it should respect the world body's decision and use it as a mirror to correct its own perception of history.

Japan's unwarranted accusations also evidence its intention to impose its own flawed values of justice and twisted perception of history on others.

Including the documentary heritage submitted by China in the world's memory will play a positive role in cherishing peace and safeguarding human dignity.