At the G20, Mr. Xi met Mr. Trump again. They have a big problem to fix. Their economies are at war, and the war is not one of necessity, but choice.

America chose to start a trade war with China a year ago. Now, President Trump said there will be no new tariffs on the Chinese. That is a good sign, but not good enough for an economic relationship that still hangs in the balance.

By defying the common law of inter-dependence, America wants to punish others to get one leg up on trade deals. What America does is basically to weaponize global trading system, and the reason it can do that is the fact that America is the designer, driver and judge of the system. 

The whole world uses the U.S. dollar as a global currency, American chips as the heart of their machines and American brains as problem solvers. 

In a way, the world revolves around the U.S. It has been this way for decades, but it does not mean it has to be that way forever, especially when its leader has turned rogue and is trying to undermine the world by abusing his country's position.

Be it Mexicans, Canadians, Europeans, Japanese, Koreans or Chinese, the message from the U.S. is loud and clear: Everything is up for grabs, and anything could be for sale. 

In the eyes of the Trump administration, allies are free riders and opponents are devils. This is nothing short of pure short-sightedness. America maybe wants to right the wrongs of trade but its methods could leave it on the wrong side of history.

But the trade dispute is not everything, there is a bigger problem to fix, which is, how to define the relations between China and America. There are strident voices on both sides saying to treat each other as arch rivals.  

In Wednesday’s De­mo­c­ra­tic pri­mary de­bate, four of 10 can­di­dates picked China as America's great­est threat. And here in China, more and more people think America is turning its back on its biggest economic partner.

As the Chinese saying goes, "Whenever there is imbalance, there is outcry." Rebalancing usually takes time and puts a toll on the world. The pre-1914 imbalance took two world wars and decades of chaos to resolve and the China-America imbalance probably needs more time but, hopefully, no wars to fix.

Mr. Xi warned the world that we should not make historical mistakes by being myopic. But we are all humans and vulnerable to the lure of short term gains. America is still psyched up for economic nationalism and China is in no mood for capitulation. So brace yourself and hope for the best, but be ready for the worst.

Script: Zou Yue

Video photographer: Zhao Jing

Video editors: Zhu Tingyu, Li Linxi

Designer: Li Linxi

Producer: Bi Jianlu

Supervisor: Mei Yan

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