It was the 18th century French philosopher François-Marie Arouet – more popularly known by his nom de plume 'Voltaire' – who is regularly attributed with the saying: "I disapprove of what you say, but I will defend to the death your right to say it."

Freedom of expression in the West is regarded as one of the fundamental principles of a healthy democracy. So as marches across Beijing and other cities in China, demonstrating against Japan's "purchase" of the Diaoyu Islands, seem to get larger and more vocal every day, reason tells me I should be happy that this is real democracy in action, where the people can feel free to show their feelings openly over something they feel so strongly about.

But it has to be said that this morning, when my bus was diverted way off its normal route because of the protests, and I finally got to my appointment over an hour late, I was feeling decidedly less sympathetic. They may have the right to protest, but do they have the right to disrupt other people's lives to such an extent?

There are many stories of Japanese-related businesses, like restaurants and stores, being forced to close for their own safety and that of their staff and customers. Honda suspended production in China, as did Mazda in its Nanjing factory. Canon announced it would close its three Chinese factories temporarily, affecting more than 20,000 Chinese workers. Japan's Fast Retailing said it would close 19 Uniqlo outlets in China while Japan's leading general retailer announced the closure of 13 Ito Yokado supermarkets and 198 "7-Eleven" convenience stores across the country.

Just down the road from here, a 7-Eleven store has concealed its logo with banners of patriotic Chinese slogans, as has an Ito Yokado store a little bit further away. The International Youth University inside the China-Japan Youth Exchanges Center in Beijing suspended all classes, while a school for Japanese kids near Beijing's embassy quarter has been temporarily shut down, as has a German school nearby.

Over the weekend, there were reports from Qingdao that both the Toyota and Honda plants had been attacked by arsonists – a weekend, which has seen the worst outbreak of anti-Japanese sentiment in decades. Deep economic and trade ties between the two largest Asian economies are now under threat.

By sheer coincidence, I happened to visit one of Beijing's most poignant museums last week – the Museum of the War of the Chinese People's Resistance Against Japanese Aggression (中国人民抗日战争纪念馆) situated by the famous Lugou Qiao (Marco Polo Bridge) in the Fengtai District of west Beijing.

It graphically shows many of the horrors of that time, perpetrated by the Japanese invaders 80 years ago: pictures of people killed by chemical weapons; bacteriological warfare experiments; piles of murdered children's bodies; "comfort women" used by the Japanese soldiers. If anyone needs to seek a reason for the deep felt animosity of the Chinese against their eastern neighbors, they could do no better than to come here.

But equally, they should not miss out on the gallery that reflects the 60th anniversary of the Chinese people's victory in this Sino-Japanese war in 2005 which eloquently talks about an "end to former enmities and a dedication to amity" between the two nations. President Hu Jintao then urged the Chinese and Japanese peoples to be friends forever.

But with this year being the 40th anniversary of the normalization of diplomatic relations between China and Japan in 1972, one wonders if many on both sides of the current divide have learned from the bitter lessons that history can teach us all.

To quote another "philosopher" from the 20th century – John Lennon, in his first solo single in 1969 – isn't it time we "Give Peace a Chance", rather than highlight the very deep divisions between these two great nations?