The war on drugs also cannot simply be judged on statistics, it is a complex and emotive issue for society.
Baroness Meacher, chairwoman of the All-Party Parliamentary Group on Drug Policy Reform, has made the case that countries where mild drug offences have been decriminalised have lower rates of offending.
Yet all too often statistics are viewed as the most important evidence in an argument, and drug related crime can rise or fall dependent on many factors. We do not know what social changes or other initiatives have been undertaken in the Czech Republic and Portugal that could also have had a positive impact.
It is also clear that a one-size fits-all approach is not appropriate – for example this year the Dutch have moved to tighten their famously relaxed laws on low-level drug use.
Crucially, as a society, there is also the element of right and wrong. Are we comfortable saying that Britain is a nation where mild drug abuse is acceptable?
It may be that the ends – a possible fall in both drug related crime and overall drug use – justify such means, but it is a dangerous path to tread.
Not only are such changes very hard to reverse once they become legislation, but the argument could be applied to other issues, such as prostitution.
The more the lines become blurred, the harder it is for the police and the courts to be consistent.
The final issue is one of timing. With mild drug use seemingly so prevalent among the young, now is not the time to be sending confused messages to the one million 16-24 year olds out of work and education.
The future impacts of such drastic policy reforms can never be predicted. The estimated outcomes are educated guesswork at best.
With the consequences for getting it wrong potentially so damaging, now is not the time for such risks.