It should be emphasised that what Emperor Xi is doing is monstrous for a supposedly civilised nation. Taking hostages, which is what putting two Canadians on trial by a secret court on a barely credible charge of espionage, is something with which we in western Europe associate with the Middle Ages. In the twenty-first century it is, to use a vogue word, unacceptable.
However, the arrest of the Huawei executive Meng Wanzhou by the Canada at the behest of Trump's USA, accepted to be the trigger for the Chinese arrests, was shocking. I would like to think that an extradition request for an offence which is not a crime in the UK would have been turned down flat. When American draftees protesting the Vietnam war fled across the 49th parallel, Pierre Trudeau, father of the present premier, did not send them back or even lock them up. One wonders why Justin Trudeau and the Canadian authorities rolled over in the case of Meng Wanzhou. Admittedly, she has not been transported into the tender hands of the US justice system and is only under house arrest, allowed to see family and friends - rather different from the gaol in which Michael Kovrig and Michael Spavor have been kept.
There is a way out. It would involve a slight loss of face by President Biden. He would only need to withdraw that segment of the Iran sanctions which Huawei is supposed to have breached. The extradition papers could then be torn up and Meng Wanzhou released. The slight loosening of the sanctions could be presented as a Persion New Year - new century even - gesture to president Hassan Rouhani rather than a ransom payment to the Chinese.