The Wuhan Institute of Virology is a global centre for coronavirus research. File/Reuters

Who is responsible for the deaths of at least 3.5 million people from Covid? President Biden has asked the American intelligence agencies to find out. Presumably he suspects that the explanation isn’t totally innocent.

His predecessor, Donald Trump, wasn’t shy in blaming the Chinese authorities. What he called the “China Virus” was, as he put it with characteristic hyperbole, “worse than Pearl Harbour. This is worse than the World Trade Centre. There has never been an attack like this.”

The idea that the Chinese had organised some kind of germ warfare attack was as ridiculous and offensive as the Chinese counter-claim that Americans had deliberately sent the virus to China.

But the Chinese authorities had already poisoned the atmosphere and fomented distrust by seeking to cover up the outbreak for several weeks and to suppress whistleblowers. The combination of Chinese government opacity and the bluster of Trump and his allies helps to explain the very sharp increase in hostility towards China in the west, as charted by Pew’s international opinion surveys, as well as outbreaks of anti-Chinese racism.

The sense of mutual hostility and resentment was demonstrated when Australia demanded that China open itself to independent inspection of the causes of the outbreak. This, along with a considerable number of other actions, led to severe economic sanctions directed by China at Australian exports.

For most of 2020, however, the atmosphere calmed down. Mainstream scientific opinion embraced the idea of zoonotic transmission: the crossover from one species to another, as occurs in most new diseases involving viruses. China’s wildlife markets are a potential breeding ground for such transmission. The assumption has been that Wuhan’s “wet” fish and animal market was the source. China has since banned wildlife consumption and trade in recognition of the problem. However, precise evidence of the source — the “smoking bat” or the “smoking pangolin” — has never been found.

The alternative theory — of an accidental laboratory leak from Wuhan Institute of Virology, a global centre for coronavirus research, or from the Wuhan Centre for Disease Control — has been widely circulated on the internet but discounted by most scientists, and was dismissed by a WHO investigative team as “very unlikely”.

But the head of the WHO is among those not fully satisfied with closing down the laboratory leak theory, which is certainly plausible. It has happened elsewhere, more frequently than we would like to believe. Britain was responsible for a fatal leak of smallpox in 1978. China has had several such incidents, including a leak of Brucellosis in 2020 which infected more than 3,000 people in the northwest province of Gansu. Tougher rules on biosafety came into force in April this year.

Political considerations have prevented rational discussion of the issue, but there are several reasons why it is necessary to get to the bottom of the leak theory. The first is to learn lessons and ensure that such a global catastrophe as Covid doesn’t happen again. In an ideal world, the Chinese authorities would embrace transparency and the search for truth. They would be given credit for opening up their facilities and subjecting the findings of their epidemiological research to independent international inspection.

A related point is that scientists working in this field, in Wuhan and elsewhere, have been experimenting with making the infections worse than their natural form in order to better develop treatments. This so-called “gain of function” research is a form of human meddling which could create bigger problems than it solves, and should stop.

The suspicion of the Chinese that demands for inspection are designed to score propaganda points and humiliate them may be eased by the suggestion that the Wuhan Institute of Virology was co-funded by the US National Institutes of Health. The idea that a disastrous leak might have emanated from a collaborative project between American and Chinese scientists is certainly a neat way of diffusing blame.

Either way, this vast human tragedy risks being subsumed within the propaganda of the new Cold War between China and the United States (and its allies, including the UK). From an American perspective, what is particularly galling is that the Chinese seem to be winning. After the negative impact of the initial outbreak and cover-up, the Chinese got a lot of credit for their effective, ruthless lockdown — which appears to have been very successful, in marked contrast to the stumbling efforts of the world’s leading democracies.

The Chinese have also scored points by making their vaccines available to the world, in contrast to alleged “hoarding” by the west (Britain’s AstraZeneca being a very honourable exception). It appears that the Chinese Sinopharm vaccine, in particular, is not as effective as the western (or Russian) alternatives, but for countries in Latin America, Africa, and eastern Europe it has been better than nothing. Now China is vaccinating its own population with great speed.

President Biden’s decision to shift the debate back onto the origins of the pandemic may be partly motivated by a wish to reclaim the moral high ground in this propaganda war. The fact that he is so careful in his language, in contrast with his predecessor, makes him a very plausible proponent of the western case. But I somehow doubt that the CIA investigation, which is due to report in just under 90 days, will be a game-changer. We have all become cynical about “dramatic revelations” and “dodgy dossiers”.

Instead it will be another episode in the Covid blame-game box set, illustrative of a wider breakdown of trust between China and the west. The west has adopted a strategy of “calling out” China with strong public denunciations on a variety of matters, notably those involving human rights. Now we have turned our attention to its record on biosafety. It makes us feel good, no doubt, and is sometimes merited, but it has no impact on the behaviour of the Chinese leadership. It merely reinforces the assumption that the west is out to humiliate China in public.

One practical consequence of a propaganda war is that both sides start to believe their own version of the “truth”. Cooperation becomes impossible. Constructive initiatives become devious ploys. The fact that pandemic prevention and management constitute an international public good takes second place to the opportunity to score a point. Finding the smoking bat, or the lab leak, becomes more important than dealing with the problems of the pandemic itself.

The risk for the whole world now is that the same happens on climate change, nuclear proliferation, and other areas in which we need the Chinese to be allies, not adversaries.