‍By CGTN's World Insight

December 13th was China’s fourth National Memorial Day to commemorate around 300,000 Chinese people killed at the hands of the Japanese invaders in the then capital Nanjing in 1937.

But 80 years on, how has the world reflected on the Nanjing Massacre?

"It's a very important time, most Japanese love peace, actually they know how the Chinese people feel about it, but there still exists a gap," said Yoshikazu Kato, a research fellow of the Charhar Institute and columnist for The New York Times Chinese web edition.

"For Japanese people, it's a good time to know more about how Chinese people feel about, I am glad to see a lot of Japanese media are reporting this ceremony, it's time to know more history."

To fill the gap, Japan has to face history honestly.

"It's important the way countries deal with their own history, no country wants to deal with the negative side of its own history, no country wants to deal with the tragedies its people have committed," said Peter Kuznick, a professor of history and director of the Nuclear Studies Institute at American University.

He said that Germany has been honest about the past but that Japan has done a comparatively poor job, with some denying the Nanjing Massacre ever happened and official history books even downplaying or whitewashing the events of 1937.

This has presented China with something of a dilemma.

"On one hand, we are upset about Japanese resistance to recognize the truth of history, but on the other hand we desperately need a shared future, but a shared future should be based on the acknowledgement of our shared history, the dark pages of history shared by China and Japan, we need to have the common sense and common acknowledgement and common values about that dark page of history. Unfortunately, we haven't reached it, we need to make constant efforts to reach that goal," said Yang Xiyu, a Senior Fellow at the China Institute of International Studies.