THE British war on drugs has been going on for nearly two centuries, I told a bemused American friend earlier this week, adding that for a large part of that time it was a war pushing drugs, not trying to eliminate them.

We were discussing the article by Chief Constable Mike Barton of Durham Police who last weekend complained that the current approach to hard drugs put billions in the hands of criminals.

He suggested that if hard drugs like heroin and cocaine, as well as ‘soft’ ones like marijuana, were legalised then there’d be less criminality, and we could concentrate on reducing harm.

He called for an “honest debate”.

I agree with him about that. We should always test policies against their objectives and not assume that what we’re doing today we’ve always done.

Indeed in the 19th century, Britain’s aim, backed by its military, was to maintain the drug trade. Opium, grown in British India, was highly profitable when sold in China; never mind the millions of addicts it was feeding.

When the Chinese emperor tried to ban the trade, the British navy moved in. There were ‘opium wars’ against the Chinese. We won both. That experience, however, is one reason why I’m so sceptical about Mr Barton’s views. For sure, it was not common criminals who controlled the drugs trade at that time, but respectable upper-class figures.

But, as the Chinese emperors kept pointing out, an open trade in drugs meant high levels of consumption.

We know from statistics that levels of smoking are in part related to price. So in a legalised drug market, governments would have to impose special duties to keep the price high.

That in turn could lead to smuggling and other criminality. The crooks wouldn’t pack up – just change how they do business.

Another difficulty, of many, is that it’s almost impossible to see how one country could go it alone without becoming a world centre for the drugs trade.

The current anti-drug strategy is far from perfect. But illicit drug use is falling. Legalising hard drugs would, I believe, create more problems than it would solve.