New Zealand's nine-month experiment with "legal highs" is over. The Government's decision to cancel interim licences for synthetic cannabis is a response to a public outcry that has left all sides wiser. Nearly all parties in Parliament voted for the licensing regime last July. The Psychoactive Substances Act passed by 119-1. The solitary MP who has been vindicated by events is Act's John Banks.
All other parties accepted the idea that drug regulation was preferable to prohibition and that some of the manufactured "party drugs" that have appeared in the past six years would be capable of passing a reasonable safety test. The lawmakers were so confident on that score that they wrote an interim licence into the legislation so that not all brands would be taken off the market while rules for clinical trials are finalised.
Of about 200 brands of synthetic cannabis previously on sale, 42 have been granted interim licences since July. It is not clear how health officials decided the 42 were relatively harmless.
If they were not among the products whose users had previously arrived at hospital emergency clinics, reports of human damage have not ceased since July.
The mother of a Tauranga youth who committed suicide after smoking the drug had nearly 30,000 supporters on her Facebook page calling for a ban. People have marched in the streets of 23 towns around the country. Newspapers and television programmes have featured pitiable cases of addicted users and damaged families.
In the face of the mounting evidence, the Government is right to retreat. Its mistake was to listen to advice that some untested products could be assumed to be safe. It may be that the number of synthetic-cannabis casualties is no greater than the ratio of alcohol users who cannot safely consume society's most popular recreational drug, but legalisation should have waited until the risk could be assessed.
The Ministry of Health was given a year from July to finalise its clinical trials. They are expected to be as rigorous and expensive as those for medicine, though the bar will not be as high. To be approved, they can carry "low risk" which, the ministry says, will not mean no risk.
Associate Health Minister Peter Dunne insists the backtrack on interim licences does not amount to prohibition, which he has argued does not work. But prohibition does work in so far as it deters some people from using a substance that could do them harm. Mr Dunne wonders why he did not hear of the harm done by these products in the years before they were regulated. Quite likely, users were on the stronger products previously.
When Parliament next week passes a bill revoking interim licences for these substances, they will be prohibited for the foreseeable future. It will take years for any of them to be proven low risk, if indeed the ministry can devise a testing regime. That task is taking an eternity. It will be more difficult if the use of animals is properly forbidden for trials of recreational drugs.
Licensing can be effective when it is limited to standards of safety or quality for a product and its suppliers. But if licensing also seeks to control the number and location of outlets for the product, perverse consequences can follow. Councils tend to approve outlets for the likes of drugs and gambling in poor communities, and limit the number so severely that users become highly visible in the few unfortunate places.
Parliament took a brave, experimental step nine months ago. When it takes a step back next week, all parties will be obliged to admit they misjudged the community's tolerance of this unseemly trade.