When the siren remembrance first began, everyone stopped, exactly where they were, frozen to symbolise that China effectively stopped under Japanese occupation. Cars stopped and passengers stood next to their vehicles. Factories fell as silent as practicable. Now, As China's population has grown, and survivors become ever fewer, the original recognition of the sirens been watered down. Now, hundreds of millions of Chinese say a quiet prayer and go about their business in a more sombre mood. The sense of common cause is palpable.

The Japanese invaded and occupied northern China in 1931. They built infrastructure, particularly railways and stations, for military purposes, readying for their drive south.

Hugely out-numbered by the Chinese, they adopted tactics of the utmost brutality. Their advance was prefaced by bombing with chemical weapons, examples of which still surface in, for example, Harbin and cause injury to anyone who touches them.

It was in Harbin, a part of China that had, until the early 20th century, been part of Russia, that the Japanese built their first torture and experimentation centre, Unit 731. The horrors visited upon the inmates make those of Nazi concentration camps, even the activities of Josef Mengele; seem mild. Yet none of those guilty at Unit 731 have ever been charged with war crimes.

As the Japanese moved south, the city of Nanking / Nanjing stands out as the location of some of the worst brutality in any war since the Middle Ages.

By the time the Japanese had over-run most of South East Asia in the early 1940's, overt resistance was minimal. In Malaya, the British, outflanked, outnumbered and with their supply lines almost destroyed, to say nothing of the increasing need to defend the U.K. against possible invasion, abandoned the area.

The Japanese piled in, targeting Chinese communities for barbaric attacks on women and children and murderous roundups of Chinese men.

You will read nothing of any of this in Japanese history books which have, in recent decades, been revised so that even some of Japan's diplomats posted to other countries in the region have no knowledge of the events and are initially disbelieving.

In the U.K., while European events are covered multiple times in the school syllabus, no mention is made of the horrors visited on the Chinese by the Japanese. The entire UK education system and its successive governments appear to be deniers of Chinese suffering while constantly pushing the suffering in Europe: in other countries, to be a "Holocaust Denier" is a criminal offence while teachers are almost required to deny the actions in Asia. It's a disgrace.

Today, as on this day every year, China remembered.

It's time the rest of the world began to find out, and record, document and teach, before Japan's tactic of waiting for the witnesses to die succeeds.