The Australian government's call for an outside inquiry into the origins of the COVID-19 virus in Wuhan has provoked a furious Chinese reaction against Australia.
Should we believe the Chinese version that it originated in a Wuhan wet market? And what's the likelihood of COVID-19 being linked to a Chinese biowarfare program?
Biological warfare (BW) is the use of biological toxins or infectious agents such as viruses, bacteria, and other toxins with the intent to kill or incapacitate humans, animals or plants. Those entities most likely to use biological weapons are nation-states and non-state actors, such as terrorist groups.
In the secretive world of biodefence, scientists examine whether a highly contagious novel coronavirus like COVID-19 could be used as a bioweapon.
Is it likely that China was trying to weaponise COVID-19? - probably not.
Viruses are not normally considered to be useful military weapons because they need a living host to survive and cannot be effectively controlled.
It is difficult to use them in a way that only affects the enemy and does not cause "blowback" to affect one's own forces or population.
Coronaviruses are a subset of viruses that cause diseases in mammals and birds.
There are no vaccines or antiviral drugs to prevent or treat human coronavirus infections - which makes coronaviruses even less useful as biological weapons.
Bacteria, which are more stable and not as contagious, are a much more attractive option for bioweaponisation. For example, anthrax (which is not contagious) could be used to target an enemy-held area. The area could then be decontaminated when one's own forces get there.
However, notwithstanding such options, nation states' use of biological weapons has been prohibited for nearly 50 years.
The main prohibition treaty is the 1972 Biological and Toxin Weapons Convention (BTWC) which proscribes development, stockpiling, producing, or transferring biological agents and toxins for potential military purposes.
One-hundred and eighty-two countries, including Australia, have ratified the BTWC. None of them is known to possess offensive BW programs - but eight are suspected of having them (namely Algeria, China, Egypt, Iran, Israel, North Korea, Russia, and Syria.)
Some American conspiracy theorists suggest that China deliberately released COVID-19 to damage Trump and the US economy. But a deliberate release seems highly unlikely.
Sixteen countries have "defensive" research programs, ostensibly to keep up to date with BW technology: Canada, China, Cuba, France, Germany, Iran, Iraq, Israel, Japan, Libya, North Korea, Russia, South Africa, Syria, the UK and US.
Turning back to COVID-19, the Trump Administration (keen to distract from its own failures) has touted the possibility that the coronavirus was accidentally leaked from the Wuhan Institute of Virology (WIV) - but that could prove embarrassing given the US's connections to the WIV.
The WIV's National Bio-safety Laboratory was completed in 2015 with partial funding from the US. A portion of US$3.7 million in research grants by the US National Institute of Health (up to 2019) helped fund research at the WIV into bat coronviruses. (Many coronaviruses have their origin in bats; COVID-19 has 96 per cent similarity to coronavirus in horseshoe bats in southwest China.)
The laboratory also has strong ties to the Galveston National Laboratory in the University of Texas.
In early 2018, US officials visited the WIV and cabled concerns to Washington about the inadequate level of safety at the research laboratory, noting that the lack of tight safety measures for handling contagious viruses in the lab "represented a risk of a new SARS-like pandemic". The cables proposed additional US support to the lab to improve its security - but no support was forthcoming.
That may have been a costly mistake. SARS in 2002 killed less than 1,000 people, but since December 2019 COVID-19 has probably killed close to half a million people (including probably 100,000 Americans). (Most COVID-19-related deaths have not been attributed to COVID-19 due to lack of test kits or deliberate cover-ups.)
China asserts that the first crossover of COVID-19 from an animal to a human occurred at a wet market in Wuhan, most likely the Huanan Wholesale Seafood Market (which also sells wild animals). But some researchers claim that the market didn't sell bats and that the first known patient, as well as many other early patients, didn't have any connection to the market.
On April 19, Dr Deborah Birx, the Coronavirus Response Coordinator for the Trump Administration's White House Coronavirus Task Force commented that she did not know precisely where it [COVID-19] originated, and right now, "the general consensus is animal to human".
Some Trump supporters suggest that China deliberately released COVID-19 to damage Trump and the US economy.
But a deliberate release seems highly unlikely.
China is usually cautious in its dealing with the rest of the world and would be very unlikely to deliberately start a pandemic that would have unpredictable consequences for China and its economy.
The WIV is a credible candidate for the start of the outbreak, but we can probably rule out any likelihood of deliberate release of COVID-19, or any association with a Chinese BW program.
If the WIV does prove to be the source of the pandemic that would be a pity from an environmental perspective as it would take the heat off China to close its repugnant wet markets and unsavoury trade in wild animals.
- Clive Williams is a visiting professor at the ANU's Centre for Military and Security Law and is a former Defence CBRN analyst.