If the US president really bars Chinese students and researchers from entering the United States, he will have broken the last of the two promises he made to his Chinese counterpart in their last conversation. 

Speaking by phone on March 27, the US leader pledged that the US would take good care of Chinese students, saying educational institutions in the US would not be the same without them, and that the US would cooperate with China in pandemic control and vaccine research. Neither his stated appreciation of China's effective control of the pandemic at home, nor the gratitude he expressed for China's assistance to the US, which he emphasized in the conversation, have resulted in any substantial pandemic control or vaccine research cooperation between the two countries.

Instead, since then, while China has remained committed to trying to fulfill its obligations in the "phase one" deal with the US and help the world, including the US, fight against the virus and sustain the global supply chains, the US administration has tried its utmost to smear China's efforts to contain the contagion at home, badmouthed almost everything related to the country and called for a global coalition to stand against it on almost every front.

Now, as US Secretary of State Mike Pompeo said in an interview on Monday, the US president is evaluating whether to stop Chinese students and researchers from entering the country, on the grounds that this will limit China's ability to use student visa programs to place people in US colleges and universities to steal US intellectual property. An allegation that is being pushed ahead of the election with the claim that it costs US jobs.

Ironically, it is the two countries' deep engagement that has developed over the past 40 years that has provided the incumbent US administration with so many means to hurt China. In spite of the US administration's flip-flop over its words, and the paranoia it has demonstrated in its China policy, China has exercised considerable restraint to try and prevent tensions from escalating. All the countermeasures it has taken so far against the US provocations have been rational and less than called for.

But although Beijing values a healthy Sino-US relationship, it will not tolerate its development interests being harmed and the common interests of the world being hijacked by a handful of political speculators. If Washington indeed puts the Chinese students in its crosshairs, China will be left with no choice but to respond.

The US leader admitted in an interview with Fox Sports Radio on Aug 11 that he has not talked with his Chinese counterpart "in a long time". Rather than blaming China for that, he should look to himself and his top diplomat for the reasons why the "great relationship" the two leaders had has "frayed".