What makes a good peace mediator?

Brokering peace between warring nations, how does it work and what causes failure? We look at Qatar’s role in the Middle East and at insight gained from the Northern Ireland peace process. Host Claire Graham talks to Lyse Doucet – the BBC’s Chief International Correspondent about how the state actors in peace mediation have changed and adapted over time. Plus Lyse tackles the question - can you really be a mediator if you are not neutral? Produced by Cathy Young for the BBC World Service.