More double standards were evident at the Normandy ceremony. British Prime Minister David Cameron refused to even shake hands with Russian President Vladimir Putin. And US President Barack Obama openly showed his contempt for the Russian president. In a video footage of the two men together, a smiling Obama appeared to be restraining himself only with difficulty from patting Putin condescendingly on the head.

Yet Putin, like President Xi at the Marco Polo Bridge, had a solemn presence in Normandy, representing a great nation that lost millions of its people in World War II. The Soviet Union lost about 27 million people, 25 times more than the combined death toll of the British Empire (then covering one quarter of the world) and the United States. China's losses too were much greater than the combined Western figure.

Therefore, China is rightly worried about Abe's move to change Japan's pacifist Constitution, which the victorious Western powers, led by the US, helped prepare after World War II. Abe has repeatedly argued that it's time Japan got back its status as a "normal" nation. But the harsh truth is that the actions of imperial Japan from 1931, when it occupied Manchuria, to its surrender on Sept 2, 1945, were anything but normal. Like Nazi Germany, the record of imperial Japan in the 1930s and 1940s is one of the darkest in human history.

Besides, Abe's timing could not have been worse, for this year also marks the 100th anniversary of the start of World War I and the 120th anniversary of the beginning of Japan's 1894-95 war against China. Utterly forgotten in the West, this epochal event in fact launched a dark 50-year period when a powerful, Westernized and militarized Japan routinely plundered China and massacred its people with impunity

This is another reason to welcome Xi's efforts to throw more light on the unbelievable war crimes and biological "experiments" carried out by the Japanese military on hundreds of thousands of helpless Chinese and other prisoners by the infamous Unit 731. These "experiments" remain, almost 70 years after the end of the war, almost unknown in the West although they were as (if not more) diabolical as those conducted by Josef Mengele and his colleagues at Auschwitz.

If Japan is to succeed in its desire to be finally recognized around the world as a "normal" nation, it needs to do what Germany has repeatedly and admirably done, from its first chancellor Konrad Adenauer to current Chancellor Angela Merkel. Japan has to openly accept that it did commit war crimes, many of them heinous, and make generous restitution to Chinese survivors or their descendants.

Until then, a dark cloud will remain over the ties between the two great nations of Northeast Asia even if they build the strongest diplomatic and economic relations.

Unfortunately, it is unlikely that Western leaders will follow Xi's example and use these anniversaries as opportunities to recognize the sufferings of hundreds of millions of people and show the world how their memory continues to shape the international order today. And that would be a dangerous mistake, because, as Spanish philosopher George Santayana has said, "those who do not remember the past, are condemned to repeat it".

The author is chief global analyst at The Globalist, a senior fellow of the American University in Moscow and has the book, Shifting Superpowers: The New and Emerging Relationship between the United States, China and India, to his credit.