Chilean firefighters extinguish burning buses during clashes between protesters and the riot police in Santiago, on October 19, 2019. Chile's president declared a state of emergency in Santiago Friday night and gave the military responsibility for security after a day of violent protests over an increase in the price of metro tickets. Photo: AFP

Radical demonstrators in Hong Kong held unapproved protests on Sunday in which mobs continued their damage to public facilities. But this weekend, at least three important cities in the world witnessed serious violence, and Hong Kong was just one of them. Similar violent attacks also took place in Catalonia of Spain and Santiago of Chile.

It's rare to see serious violence occur simultaneously in more than three big cities in the world. Extreme forces in Hong Kong have led the trend of violence. Catalan protesters have declared they have learned from Hong Kong tactics and sworn to turn Catalonia into another Hong Kong. Protesters in Santiago covered their faces with hoodies and masks like mobs in Hong Kong. Earlier, radical environmentalists disrupted traffic in places including London, a common tactic of Hong Kong violent protesters.

Hong Kong demonstrators are exporting revolution to the world in an unexpected way. The violence may spread to the center of the West. The West has been collectively supporting the Spanish government in cracking down on the separatist movement in Catalonia. 

Now Catalan protesters are taking a lesson from Hong Kong, the West can't convincingly separate riots in Europe and South America from those in Hong Kong.

The West is paying the price for supporting riots in Hong Kong, which has quickly kindled violence in other parts of the world and foreboded the political risks that the West can't manage. 

Thanks to the "one country, two systems" principle, violence in Hong Kong will only temporarily upset China, but supporting violence contradicts the basic attitude against violence in societies that adopt a Western system, posing a long-term threat to the Western system.

Rioters in Hong Kong have been avoiding police with flash mobs, but violence is flashing in other cities that implement the Western system. The trend won't be decided by Western political and opinion elites. 

The world must unanimously oppose violence that challenges the rule of law. Elites in the US and the West support the undermining of the rule of law in Hong Kong out of geopolitical considerations, but the consequences are out of their control. They have created chaos in larger areas.

Riots are justified in some places but won't be tolerated in other places. The double standards have wreaked havoc globally. The abuse of the standard will hit the boundary in reality. 

Rioters in Hong Kong have set off this round of global violence. They should reflect upon themselves. With the spread of Hong Kong-style violence, Hong Kong rioters will receive less praise from the Western world. They will gradually become an eyesore in the world.