Not content at building a "wall" dividing Hong Kong into a normal metropolis and an anarchic city, rabble-rouser Joshua Wong compared Hong Kong to Berlin during the Cold War. However, his remark may impress his Western backers, particularly the United States which has openly supported the rioters in Hong Kong, not those who see through the demonstrators' ploys.

To add drama to his visit to Berlin on Monday, Wong climbed to the top of the Reichstag building, which contains the ruins of the Berlin Wall, to air his views.

Despite his divisive views, however, the German Foreign Minister Heiko Maas chose to meet the troublemaker, sending all the wrong messages just days after German Chancellor Angela Merkel, accompanied by a large business delegation, concluded a productive visit to China.

One expected the German minister to use better discretion, in order to avoid casting a shadow on Sino-German relations.

Perhaps Western politicians have been swayed by the demonstrators in the Hong Kong Special Administrative Region as they are demanding more freedom, even pleading with Washington to "liberate" the city. But this open invitation to a foreign power to interfere in China's internal affairs is not only a violation of the "one country, two systems" principle but also tantamount to crossing the bottom line of China's sovereignty.

The fact that Wong has been able to travel out of the SAR, first to the Taiwan island and now to Germany despite being out on bail, should impress upon those supporting the demonstrators that Hong Kong residents enjoy more freedom than people in many parts of the world.

For example, on the Human Freedom Index, the most comprehensive global freedom index, Hong Kong ranks third in the world.

Yet the Hong Kong demonstrators have appealed to the US, which ranks 17th, to get them more freedom. They have also said they hope to "have a great result like Ukraine" when ironically Ukraine ranks 118th on the Human Freedom Index.

By calling white black neither the demonstrators nor their foreign supporters can turn fiction into fact. Seeking more freedom in Hong Kong is beyond shooting for the sky, and yet Carrie Lam Cheng Yuet-ngor withdrew the bill to amend the extradition law in the hope that it would drive some sense into the demonstrators.

Thanks to the mayhem created by the demonstrators, the number of tourists the SAR received in August, a peak tourist season, plunged 40 percent year-on-year, dealing a serious blow to one of its pillar industries.

This should make the demonstrators realize that by continuing to hold the city to ransom, they are shooting themselves in the foot.