Hello and welcome to the intelligence from The Economist.

I'm your host, Jason Palmer.

Every weekday, we provide a fresh perspective on the events shaping your world.

The city of Vancouver has a progressive plan to address its crisis of drug overdoses, decriminalizing all drugs.

The aim is to reduce the amount of the stuff on the street that spiked.

We ask how likely that is to work and how the plan might go wrong.

And we take a look at Africa's click languages, in which a vocal click forms a core part of communication.

Most have died out altogether,

but there's a hopeful bid to save one of them

that has just two native speakers left.

First up, though, today marked the 70th anniversary of the United Nations Refugee Convention, a landmark treaty that established the obligations that countries have to people fleeing persecution.

A core principle is non-refoulement that migrants should not be returned to a country where they

face serious threat of persecution. But in recent years, the Refugee Convention has become

perhaps the least popular treaty in the rich world.

In 2015, millions of asylum seekers, many fleeing the civil war in Syria, tried to reach Europe in any way they could.

Men, women and children, the beaches covered in life jackets and the remains of rubber boats,

relentless waves of people washing up

on the shores of Greece. News reports were flooded with images of people making a desperate and

often deadly journey. Arriving at a gateway to Europe, boats packed with migrants and refugees

continue to land on the shores of the Greek island of Lesbos. Boats packed with migrants and refugees continue to land on the shores of the Greek island of Lesbos.

Boats packed with migrants and refugees. The law makes a sharp distinction between the two,

the difference between seeking shelter and simply seeking a better life. That's a hugely

...