The first international drug treaty was signed a century ago this week. So what was the war on drugs like in 1912?

Today it is taken for granted that governments will co-operate in the fight against the heroin and cocaine trade.

But 100 years ago, narcotics passed from country to country with minimal interference from the authorities. That all changed with the 1912 International Opium Convention, which committed countries to stopping the trade in opium, morphine and cocaine.

Then, as now, the US stood in the vanguard against narcotics. While the UK's position is unequivocal today, a century ago it was an unenthusiastic signatory, says Mike Jay, author of Emperors of Dreams: Drugs in the Nineteenth Century.

The real concern a century ago was over alcohol, he argues. "There was a big debate over intoxication as there was concern about the heavy, heavy drinking culture of the 19th Century."...