For the first time in living memory the Proms season (which opens next Friday) is not graced by a single American orchestra. The loss is far more than just musical. Those visits by brash, brilliant New York, refined Boston, precision-made Cleveland, powerhouse Chicago and aristocratic Philadelphia, just to name the traditional “Big Five” (most US critics would add San Francisco, Los Angeles and Minnesota to this musical Ivy League), were great transatlantic occasions. To enter an Albert Hall packed with Americans — in the stalls as well as on the platform — was to be forcibly but not unpleasantly reminded that London has more US citizens living and working here (some 250,000) than most cities in the US. Such nights were exuberant tribal gatherings as much as concerts.

They were also opportunities for British connoisseurs to measure those mighty beasts not just against each other, or British orchestras, or Vienna and Berlin, but against past recordings of themselves. Is Cleveland playing as well under Welser-Most as it did under Dohnanyi? Has Chicago lost its edge since Solti died? Such discussions may seem esoteric, but in the competitive orchestral world they certainly matter. Sponsors, audiences and record-buyers want the best, not the has-beens.

Well, the recession has clobbered all that. Touring an American orchestra in Europe was always dauntingly expensive. (According to an old joke, the Chicago Symphony Orchestra always required two juggernaut lorries — one for their instruments and one to carry their supply of bottled water in dangerous Third World countries such as France.) But the rising cost of air freight and the sudden scarcity of corporate sponsors (at least $3 million is needed to tour a US orchestra in Europe) have made matters worse. So have tighter security requirements, which mean that vital hours are forfeited in tight schedules while expensive musicians hang around airport check-ins.

And now there’s a big question mark over visas. British orchestras touring the US have to go through extraordinarily time-consuming vetting procedures; and the British immigration authorities are imposing far more rigorous tests on foreign performers wanting to come here. The Iranian film director Abbas Kiarostami says that he was treated so disrespectfully by the British Embassy in Tehran when applying for a visa to direct Così fan tutte at ENO this summer that he gave up. He tried to direct the opera by e-mail instead. Unsurprisingly, that didn’t work too well.

His case is not rare. Non-EU musicians, ballet dancers and painters have all been hit by stringent new requirements to produce biometric data and a digital picture, evidence of financial support and a sponsor who guarantees to monitor them while they are in the UK. Festivals and art forms that rely heavily on artists from the Far East, Africa and South America — world music and salsa, for instance — have been particularly hit. But there are cancellations across all genres.

So if the recession doesn’t kill off international touring, it looks as if government officials around the world — prominently including those in our own dear Home Office — are determined to do the job instead. What will be the consequences?

Well, first consider how artists and performers benefit from seeing what people are doing in distant countries. Think of the influence of African art on Henry Moore, or Tahitian culture on Gauguin. Think of the shock to complacent British performers when the dazzling Bolshoi Ballet first appeared here in 1956, or the Berlin Philharmonic in the 1920s. Think of how the sounds and philosophies of wonderful world-music performers have seeped into all sorts of other musical cultures. Ideas (particularly benign cultural ideas) should flow freely.

Then consider the disappointment for audiences. The internet has allowed bands, soloists and visual artists to build up global followings. But those distant fans want to see their stars in the flesh. Why is it easy for supermarkets to give us stacked aisles of fruit from other continents but increasingly difficult for impresarios to give us the fruits of other civilisations?

And finally, consider the impact on international relations. What sort of message do we send to the Middle East when we treat a distinguished, artistically brilliant Iranian such as Kiarostami with colonial-era contempt? I don’t know whether travel broadens the mind. But I know that prejudices fester in narrow minds if countries cease to be interested in each other’s culture. And while it is fashionable to decry “cultural diplomacy”, or its big bad cousin “cultural imperialism”, I believe that it’s a lot healthier to try to win over foreign hearts and minds with music, dance and theatre than it is with nuclear stockpiles.

So let’s hope that this madness — financial and political — passes soon. “Nation shall not speak peace unto nation” isn’t a good motto for any age. Certainly not for one as volatile as ours.

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