Canada has just taken the bold step of legalising recreational cannabis – making itthe largest country in the world with a legal national marijuana marketplace. An article I wrote some time ago for City AM offers a reminder of the tremendous opportunities of cannabis legalisation, should Britain be bold enough to seize them.Earlier this year, it was revealed that Donald Trump is working on legislation that would “unambiguously allow states to pursue (marijuana) legalisation without worrying about a federal crackdown”. If implemented, this would be a dramatic shift away from how previous administrations – and indeed Trump’s own White House – have handled state-based policy on drug reform throughout the years.Inconsistencies between federal and state law have long been entrenched in the cannabis debate. Despite the Obama administration’s promise to “deprioritise most marijuana-related prosecutions” in states where it was made legal, such rhetoric often failed to line up with action.According to The Nation, raids on growers and sellers actually increased after Obama’s inauguration. In June 2013, Americans for Safe Access issued a report, which “calculated that the Obama administration had spent $300m ‘interfering’ with state medical marijuana laws in the last four and a half years, outspending the Bush administration (both terms) by $100m.”The situation was feared to worsen early this year, when Trump’s attorney general Jeff Sessions overturned the Obama administration’s (theoretical) policy of not interfering with marijuana production where it was made legal by state law.Trump’s intervention should help to resolve issues of legal clarity, but more importantly, it is a signal that the federal government may be moving away from its failed drug policy.The drugs war has given an unnecessarily large number of people a criminal record, despite often being of no threat to society. According to the ACLU, “marijuana arrests now account for over half of all drug arrests in the United States”. Of these arrests, the large majority are for mere possession – not for any attempt to sell or engage in violent behaviour related to the drugs trade.Even more depressingly, black Americans are nearly four times as likely to be cuffed for cannabis-related crime than white Americans, despite roughly equal rates of usage.Meanwhile, the evidence coming out of states that have legalised recreational marijuana already is overwhelmingly positive. In Colorado, teenage use has fallen to its lowest level since 2007/2008. And it’s not simply marijuana use that’s on the decline – since legalisation in 2012, the use of alcohol, tobacco and heroin amongst teenagers has dramatically reduced as well.Trump is right to look to the evidence, and follow a path that puts public safety at the heart of the drugs debate, while tackling systematic discrimination simultaneously.The UK is falling behind countries like the US and Canada on this crucial issue. The home secretary’s “serious violence strategy’ will never fully succeed if it continues to omit drug reform from the agenda.You’ll rarely hear this from me, but this time, it’s indisputable: British policy makers should look to Trump, and follow suit.