Vancouver in British Columbia, Ciudad Juárez in northern Mexico and Helmand Province in southern Afghanistan are unlikely cousins. But together these three places and their ilk have wrought a remarkable change in one of the world’s most important debates over the past two years.

For decades, the idea of legalizing narcotics was supported by only a small minority. But as global markets in illicit drugs have expanded exponentially since the early 1990s, policy makers and law enforcement agencies alike have been overwhelmed by the challenge posed by the prohibition of a long list of drugs. Markets have spread to places that for decades had no significant drug problem, like China and Indonesia, while the numbers of addicts in countries like Iran have grown hugely.

Two significant developments are contributing to the sudden surge in calls for reconsidering prohibition. The first is that drugs are now damaging long-term Western security interests, especially in Afghanistan and Mexico. The second is that production is migrating away from its traditional homes like Colombia and the Golden Triangle and moving into the heart of Western consumer areas like Canada, the Netherlands and Britain.

The problem is becoming so dramatic that elder statesmen, senior law enforcement officers, intellectuals and philanthropists the world over are speaking out loud and clear: The “War on Drugs” is a disastrous policy that achieves none of its aims and inflicts huge damage on global security and governance wherever it is prosecuted.