Does China spy on Britain? Of course. But we have more important matters to discuss with them

At one time, Britain used to send gunboats on the Yangtze River. It will teach those Chinese. To hear some MPs talk about Beijing's spying, you'd think the gunboats were already on their way.

Of course, it is malicious and damaging for a foreign state to hack into Britain's Electoral Commission and target senior MPs - as the government claimed on Monday that China did in 2021. Forging MPs' emails and using a Commons researcher as an informant are equally malicious. No less bad is the culture of fear sown among Britain's 150,000 Chinese students by Beijing's agents, though tolerated by money-hungry British universities.

How to respond is another matter. Rishi Sunak rushed to the field. "We have been very clear that the situation now is that China is behaving increasingly assertively abroad, authoritarian at home, and that represents an era-defining challenge and the greatest state-based threat to our economic security". she said. "So, it's only right that we take measures to protect ourselves, which we are doing." It was clear. It was also funny. On Sunday night, an equally absurd BBC political bubble programme, the Westminster Hour on Radio 4, made war seem at hand. MPs claimed that the Deputy Prime Minister, Oliver Dowden, had "called China", rather than a Garrick Club rule. Beijing was "unacceptable". "Results" should be The Yangtze gunboat was clearing her decks.

But before that, Dowden was making his point. There will be a reckoning, he promised MPs, more sanctions. Ian Duncan Smith, the former Tory leader who has reportedly been targeted alongside other MPs from China's Inter-Parliamentary Coalition, was also blunt. He said China is not just a challenge for us. It must be framed as a threat. "As they grow in strength and power, we shrink before them," he said.

Still, I doubt if it even gets a news-in-brief in the People's Daily. Britain's parliament may not be a big deal in Beijing's security hierarchy. Duncan Smith's perfection could barely hold back the People's Liberation Army. It's similar to the sound and fury of the 2008 Beijing Olympics when a British minister met a Chinese host and was asked to "raise issues related to Uyghur human rights". A Chinese acquaintance told me it had become ridiculous, "like the British saying a favour or asking about the weather".

British diplomacy still exists in the mists of lost imperial power. Meanwhile, China is expanding its global influence just as the West has done. Its Belt and Road Initiative (BRI) now spans Asia, Africa and Europe. Its investments have advanced China's interests but also the lives of those it supports. The BRI, incidentally, made many gains in the City of London in construction, banking, insurance and professional services. Realpolitik is how it works. The plight of the Uighurs has not stopped David Cameron and George Osborne from begging for Chinese money for power stations and railways; Business was business.

Today the world relationship with China is very important in one respect. The country is responsible for more than a quarter of the world's greenhouse gas emissions and increasing. Britain is now actively participating in the "greening" of China's proposed BRI programme, which is mainly about infrastructure. Given that a third of all greenhouse gas emissions come from construction - a fact still ignored by British planning policy - this cooperation with China is central to tackling the climate crisis. It is not about diplomatic posturing. It is about something necessary.

The reality is that states spy on each other, mostly without effect and at enormous cost. Nothing justifies hacking other people's emails, but the aid of public outrage and some Chinese diplomats sent packing should be enough to restore Westminster's machismo. It is also clear that international action is needed to police the dark regions of the digital universe, where the entire world wanders without a candle.

But, for all these concerns, a sense of proportion is the most difficult but most necessary quality to maintain international relations. We are told every day that global warming is the biggest threat to the world right now. Unless it applies only to pre-lunch, it must be at the centre of all relations with China.