The members of the United Nations Security Council hear terrible stories from conflict zones with alarming frequency. So it takes a truly horrific tale to bring them to tears.

Yet as officials in the Council listened in December to Nadia Murad Basee Taha bravely recount her torturous ordeal as an Islamic State sex slave, some wept openly. When she fell silent, she received a rare ovation.

Murad is returning next week to the UN to be inducted as a Goodwill Ambassador for the Dignity of Survivors of Human Trafficking. Since her last visit, the Security Council has requested a report from the Secretary-General on human trafficking in conflict, and what can be done about it.

The council should act soon – because the problem appears to be rapidly getting worse.