The architect of Portugal's drug policy has rejected suggestions from anti-drug campaigners here in New Zealand that decriminalisation doesn't work.
Speaking to RadioLIVE on Sunday, João Castel-Branco Goulão told host Ryan Bridge the drug situation in his country, particularly when it comes to heroin, has improved across the board.
"The idea was that what really matters is the relationship the subject has established with the substance, and not the substance itself."
In 2001, Portugal decriminalised all drugs, provided the user only had a small amount on them. They're still illegal, but users no longer face criminal penalties.
"It's based on the idea that we are dealing with a social and health issue, rather than a criminal one," said Mr Goulão.
Combined with comprehensive treatment and support for addicts to quit, Mr Goulão said not only has use dropped, but people who do start using do so later in life, and drug-related crime has plummeted.
"I cannot tell you that decriminalisation by itself has an impact on it - the complete set of policies we put together and the capacity to treat everybody who wanted to be treated was crucial."
Bridge supports decriminalisation, writing in a column for Newshub the 'War on Drugs' was over - and law enforcement lost.
Family First chief Bob McCoskrie told RadioLIVE there never had been a war.
"I think there has been a little bit of a battle," he said, saying there was "no reason" for New Zealand to follow Portugal's lead.
"What do we mean by decriminalisation? What do we mean by legalisation? They are different, but we would argue they send the same message - either we approve of methamphetamine use and therefore we don't have a problem with it, and don't need to discourage it ; or we do need ot discourage it, and therefore we need the weight and force of the law."
He rejected Mr Goulão's claims use was down, because "legality has a huge effect on consumption", so consumption surely had risen.
"Marijuana is illegal. The use is minimal compared to smoking".
And while Mr Goulão doesn't believe the substance itself was unimportant when it came to helping addicts, Mr McCoskrie sees a huge difference between heroin and methamphetamine, and alcohol.
"It's very easy for you or I to have a glass of wine together and not have any problems, but if we were to get into methamphetamine, it would be very different," he explained.
"You just have to talk to any family that has been impacted by P, and they will do anything and everything to keep that drug out of their house and away from their family."
An argument often made by decriminalisation supporters is that it would take business away from the gangs. Mr McCoskrie says this has not happened anywhere that drugs like marijuana have been decriminalised or legalised.
"Gangs are still making huge money in Colorado [while the] Government is responsible for the social cost of the increased usage."
Mr Goulão maintains none of the warnings about increased use, drug tourism or kids having greater access to drugs have come true.
"Today 15, 16 years later, we can tell you none of those occurred."