Reportedly, four Chinese students who travelled to the United States to study and participate in academic conferences suffered from the US side's unwarranted harassment, interrogation and repatriation. All of them have scientific and technical backgrounds.

The officers with US Customs and Border Protection repeatedly questioned them about their personal and family information, whether they are members of the Communist Party of China, and whether they have cooperated with the Chinese government.

This is just the latest politicized law enforcement move the US side has taken targeting Chinese students and researchers with backgrounds in science, technology, engineering and mathematics. Such discriminatory actions started a few years ago when the US defined China as its No 1 rival.

The US actions far exceed the scope of normal law enforcement. The purpose is not to maintain the so-called national border security, but to hinder China's technological development.

In so doing, the US is poisoning the public opinion environment for bilateral relations, hindering personnel exchanges and talent exchanges between China and the US, and ultimately damaging the US' international image and its own innovation vitality.

For decades, Washington regarded well-educated Chinese youths as a key group that it wanted to influence in the hope that not only would the US benefit from China's brain drain but, more importantly, it could cultivate a pro-US stance among the elites of Chinese society.

Now, the US has done a 180-degree turn in its China policy and its politicized law-enforcement actions target this same group of people. Washington has given up its previous strategy of trying to make friends with Chinese youths, if not its hope that China can be transformed to a member of the US club by the US' "opening-up" to it.

That being said, those pointing out that the US that it is shooting itself in the foot through shutting the door upon Chinese STEM talents should be reminded that the US has already made its choice, considering that to be the lesser of two evils. Chinese STEM talents pursuing further education and research opportunities overseas need to divert their attention to other developed countries that have not yet followed the US' lead.