Hong Kong in China, and China in Hong Kong, have long been part of a larger story. The story did not begin with the handover in 1997.
Its roots go back to when, for Manchu Qing China, Hong Kong was a small island far away enough from the centre to be ceded without much pain.
If the British had behaved like the Portuguese who had gone earlier to Macau, there would have been no need to worry about them. The Portuguese had played by China's rules for 300 years before the British shot their way into China.
As it turned out, Hong Kong developed very differently. Beyond being an open door for foreigners to enter China, it was also one for Chinese to leave and seek better livelihoods elsewhere.
It was a market place, a haven, and, for someone like Chinese revolutionary leader Sun Yat-sen, a model of modern urban development that he wanted the cities of China to emulate.
Chinese enterprise played a big role in the colony's success but no less important was what the British introduced, laws that guaranteed property rights and protected the freedoms that its Chinese population could not get in China.
All that began to change after the end of World War II. The retreat of the old empires led to Hong Kong and China being caught in a fierce global struggle between capitalism and communism.
The victory of the Chinese Communist Party moved the country's ideological frontiers from its borders with the Soviet Union that Nationalist China had hoped to defend, to the long coastline of the East and South China seas.
Here, the United States Navy took over from the British and, for at least 40 years, Hong Kong unwittingly became the Berlin of the East, that is, the front-line between Western and communist power.
Thus the Hong Kong people's involvement in Chinese politics became more intense and tangled than ever before.
The communist government in China knew that the city was being used as an observation centre by the West in the Cold War.
But the city was also China's window on the outside world. The colony provided access to foreign knowledge and technology, and also enabled China to seek the resources and markets it needed.
Today, as the street protests by students continue, new actors are playing on the old streets where earlier demonstrations were held. But there are significant differences in the background.
The most important is that Beijing does not need Hong Kong the way it did from 1949 to 1997, and it is burdened by problems of governance in China that it did not have a decade ago.
No less important, however, is that London and its North American and European allies are wearied by unending conflicts all over the Eurasian continent. There is thus an air of helplessness that seems to be sapping hopes of Hong Kong converging peacefully with China.
Chinese leaders have observed the changing population of Hong Kong with keen interest. Those who arrived in Hong Kong early prospered by acting as a bridge between China and the outside world. Those who came later included many who fled their homes in China for livelihood or political reasons. Among them were those who nurtured dreams of more perfect worlds far away. Yet others remained and learnt to serve different masters in the city and in China as well.
Hong Kong had always been a restless city that attracted risk-takers no less than refugees. It has been home to people of different ideological stripes. The people prided themselves on their revolutionaries such as Sun Yat-sen and also sheltered the communist enemies of his Nationalist Party.