After the Apple Daily founder, Jimmy Lai Chee-ying, was found guilty of three national security crimes, his trial concluded on Monday with the imposition of the sentences.

A three-judge panel of the Court of First Instance unanimously convicted him of two offenses of conspiring to collude with foreign forces to endanger national security (contrary to the Hong Kong SAR National Security Law, NSL Art.29), and one offense of conspiring to publish seditious material.

These were serious charges, and the punishment was always going to be severe. The minimum sentence for collusion under the NSL for a grave offense is 10 years' imprisonment, and the judges ruled that the involvement of foreign entities was a factor that increased the gravity of the crime. Whereas Lai was sentenced to 20 years' imprisonment overall, his eight confederates, who pleaded guilty, received terms of up to 10 years, while his three companies were fined. As Lai was considered "the mastermind and the driving force behind these conspiracies", his greater culpability, coupled with his lack of remorse, justified his higher sentences.

Although 20 years' imprisonment is undoubtedly a significant punishment, it is by no means disproportionate to the sentences for other serious crimes. For example, drug traffickers, bank robbers and bomb-makers will also be severely punished, and their terms sometimes exceed 20 years' imprisonment. The guiding principle is invariably that the punishment should fit the crime.

Moreover, the classical principles of sentencing guide the courts, particularly in cases involving grave crimes, and they were relevant to Lai's sentencing. The principles were developed by the English Court of Appeal in 1974 and have since been adopted in many common-law jurisdictions, including Hong Kong.

The first principle is retribution. By that the Court meant that society "must show its abhorrence of particular types of crime, and the only way in which the courts can do this is by the sentences they pass".

The second principle is deterrence. This involves not only deterring the individual offender but also others of a like mind who might be tempted to commit similar offenses in the future.

Nobody, therefore, should be surprised, given the enormity of his crimes and the importance of deterring others, that both principles played their part in Lai's sentencing process.

His imprisonment, moreover, has also, despite his age, provided the community with a measure of protection (prevention being the third principle). There are still people who would like to weaponize Lai to China's detriment if he were at large, and he could play along. His removal from society ensures, as the Hong Kong Court of Appeal (CA) put it in 1987," the offender cannot offend again".

In 1988, moreover, the CA also explained that the public interest requires that defendants who commit very serious offenses "should be visited with condign punishment sufficient not only to achieve a substantial measure of retribution but also to protect the public by deterring others from committing this type of offense".

Throughout his trial, Lai was ably represented by a legal team comprising no less than six barristers, ably led by Senior Counsel Robert Pang Yiuhung and including King's Counsel Marc Corlett. In mitigation, everything that could be said to reduce Lai's sentences was urged upon the judges by Pang's team. However, as they must have realized, their task, given the magnitude of Lai's offending, his absence of remorse, and the statutory minimum sentence of 10 years' imprisonment for collusion, was never going to be easy.

The judges are highly experienced jurists, with extensive experience in criminal law (including sentencing). They were at pains to emphasize that Lai was not tried for his views or beliefs, but for his leadership role in hostile conspiracies aimed at harming China, including the Hong Kong Special Administrative Region. Their task was clear, and they had to honor the evidence, which was damning.

It demonstrated beyond a reasonable doubt that Lai was the central figure in attempts to subvert China's political system and wreck the "one country, two systems" policy. He was committed to advancing the United States' interests at the expense of his own country's. It was established that Lai was obsessed with making China subservient to the US and wanted it to become a "lackey of the West".

By various means, including the use of Apple Daily and the subversive organization, Lai lobbied the US, the United Kingdom and Japan, requesting that they impose sanctions, blockades and other harmful measures on China and its Hong Kong SAR. He loathed China's political system and was prepared to do whatever he could to effect regime change. However viewed, therefore, his conduct was despicable, wholly beyond the pale.

Any country would come down like a ton of bricks on national security crimes of this sort, and the sentences imposed on Lai (and his confederates) are objectively sound.

As if this were not bad enough, Lai compounded his criminality by attempting to incite hatred of the authorities in both the Chinese mainland and the Hong Kong SAR through 161 op-eds published in Apple Daily. Although foreign critics claimed he was being persecuted for simply expressing his views, no one in their right mind could imagine that calculated attempts to destabilize the central and SAR governments had anything to do with legitimate journalistic activity.

Although freedom of the press is guaranteed by the Basic Law, it is not absolute in Hong Kong or elsewhere, and there are always red lines that must not be crossed. Lai's abuses could so easily have queered the pitch for everybody else, but he did not care.

Indeed, as the chief executive, John Lee Ka-Chiu, has explained, "The law never allows anyone, regardless of profession or background, to harm their country and compatriots under the guise of human rights, democracy, and freedom."

It is fortunate that, despite Lai's activities, Hong Kong retains a vibrant media scene.

Because of the combined effect of his age, health and segregation from other prisoners, Lai received short reductions in his sentences, although the judges emphasized that with such grave offenses, the mitigating factors had only a limited impact. After all, Lai was receiving all the medical treatment he needed, and he was segregated at his own request.

Although courts seek to accord as much weight as possible to an offender's advanced age, this is not always possible. If, for example, somebody is convicted of serious sexual offenses, particularly involving children, the courts may feel unable to give any discount to age. When, moreover, a 78-year-old drug trafficker sought to use his age in mitigation of sentence in 2000, the Court of Appeal gave him short shrift.

As Lai's offenses could have threatened the country's very survival, they fell into the worst possible category, and it was incumbent upon the judges to fashion their sentences accordingly. If Lai imagined he was above the law, he would have had a rude awakening. He has riches, power and influence, but this could not avail him when the chips were down, which many will find reassuring.

Although the trial judges faced sinister pressures from abroad, they remained true to their judicial oaths. They safeguarded the law and administered justice without fear or favor, self-interest or deceit. They remained focused throughout, acting in the highest traditions of the common law world, which is greatly to their credit.

Although Lai had great talent, he wasted it and let everybody down. While anti-China forces everywhere will bemoan his fate, justice has been done. After a trial conducted in accordance with common-law rules, Lai was convicted on all charges, and his sentences reflect his culpability.

The big winner, therefore, is the rule of law.