What wonderful news. Our government has concluded a free-trade deal with the mysterious hermit kingdom of New Zealand, which will enable the British consumer to enjoy much cheaper imports from this strange, distant land in which nobody is allowed in or out and death has been made illegal. There are many desirable products for which New Zealand is justly famous — wine, or meat and self-righteousness being just the three most renowned.

In return a strictly controlled number of British people will be allowed to view New Zealand from boats moored offshore and wave at the citizens, although as far as I’m aware they will be prevented from actually setting foot in the place. It is suggested that this deal will knock 20p off the price of a bottle of Kiwi screwtop pinot grigio and also that it has annoyed the National Farmers’ Union. So, win-win! The deal was announced in a virtual joint press conference between Boris Johnson and New Zealand’s leader, the sainted Lady Jacinda of the Perpetual Lockdown and Many Masks.

Of those famous New Zealand products, self-righteousness was the first to arrive. A rider to the trade deal is New Zealand’s insistence that the haka must not be performed “inappropriately” in the UK. I wasn’t aware that it was performed at all.

The haka is a kind of tribal war dance containing much grunting and shouting and is basically an affectation of belligerence. If anyone other than the Maoris had come up with it, the thing would have been considered the ultima Thule of toxic masculinity. Anyway, you’re not allowed to do it any more, which I’m sure has put a crimp in your evening.

Jacinda Ardern, who spends the majority of her time grovelling around the Chinese and refusing to let her people go anywhere, is resolute in her opposition to cultural appropriation. Only Maoris, then, are allowed to do the haka (apart from the non-Maori members of the All Blacks rugby team — for them it’s just fine). Jacinda is impeccably right-on, you see.

With the possible exception of the abolition of women, there is no more idiotic shibboleth in the stunted lexicon of jiggery-wokery enthusiasts than the opposition to what they deem “cultural appropriation”. It has been used to castigate students who wear sombreros, food companies that produce ready meals they dare to call “curry”, cabaret singers belting out a version of Carl Douglas’s sublime hit Kung Fu Fighting, Katy Perry wearing a kimono, rugby teams wearing Native American headdresses and people who eat rice with their meals instead of chips. There is even a growing confected anger in America over white people wearing training shoes — “sneaker culture” being a black thing, OK? Never mind that the people who invented the training shoe, for better or for worse, were white.

The point is that what they call cultural appropriation is not merely acceptable (whether done “respectfully” or otherwise) but crucial to our success as a species. The aping of customs previously foreign to us is how we learn and progress. For example, I am delighted, rather than insulted, that so many countries have culturally appropriated freedom of speech and democracy and would urge more to do the same. Cultural appropriation is why London has some of the best restaurants in the world today — and if someone from the Indian subcontinent complains about the inauthentic western take on curries, point out to them that they wouldn’t have chillies if it weren’t for the Portuguese.

The history of mankind has been a history of cultural appropriation — in art, in literature and even more so in music. Rhythm and blues from black American culture was fused with the white working-class country music to form rock’n’roll, for example. Liszt (like plenty of others) culturally appropriated the Gypsy folk music of central Europe and the result was the Hungarian Rhapsodies.

Everything that is good about us as a species has been enhanced and enriched by cultural appropriation, and you would think that the internationalist left would concur. But instead the left insists that we must all squat inside our respective ghettos, because no exchange between us can ever be quite pristine and equal. It is an absurdity.

Listen, Jacinda. I will refrain from performing the haka this evening, and I’m sure that marketing companies will likewise desist from using the dance to flog their products. The main reason I will refrain, though, is that it is a singularly stupid dance and your rugby players, Maori or white, look really stupid when they are doing it. You can keep it!