David Cameron has missed his chance to get even with Beijing. Didn't the British prime minister see Scottish separatist Alex Salmond shaking hands with State Councillor Yang Jiechi in Beijing and promising to make China a key economic partner if Scotland gains independence? "When Scotland becomes independent â€¦ there won't be a difficulty. We shall be encouraging and welcoming," said Scotland's first minister. The Chinese people must be salivating over those single malts and smoked salmon. But Beijing, of all governments, should be alert to the political sensitivity over the coming independence referendum in which the Scottish people will vote on whether to end their political union with the United Kingdom after more than 300 years. By Chinese standards, Cameron ought to be jumping up and down and screaming, "Bloody foreign interference!" - unless, of course, there is no such sensitivity from London. Salmond, however, is clearly aware of Chinese sensitivity. Last year he braved criticism when he refused to meet the Dalai Lama. He declined to comment when asked about it during this trip. You can understand why China looms large over the Scottish economy. Salmond has just ended a five-day trade visit in which 30 Scottish firms signed deals worth Â£40 million (HK$498.5 million) and hobnobbed with top executives from CNOOC and Sinopec, two major oil investors in the North Sea. Salmon exports to China have jumped by 88 per cent in five years. Non-interference has been a cornerstone of China's foreign policy. It is a perfectly valid and defensible principle. But it's foolish and counterproductive to denounce others for interfering as the default response; far better to engage your opponents in open debate. Beijing has legitimate interests in Hong Kong's political developments; its foreign policy usually has clear and justifiable rationale, including its position on sea disputes with neighbouring states. But it needs to argue for its stance and must know the world is already prejudiced against it. Its self-righteous rhetoric is often self-defeating. Western countries understand the need to confront and address world opinion. China must do the same if it is to have a fighting chance in this diplomatic game. ----- well said.