Why are states increasingly using mercenary forces?

Mercenaries are being used more widely in conflicts despite a UN Convention banning them. From the Russian Wagner Group to the former Blackwater, these organisations have been accused of widespread human rights abuses. So, why are states using them? And who's accountable for their actions?  Join Folly Bah Thibault. Guests:  Sorcha MacLeod - Chair of the UN Working Group on the use of Mercenaries. Samuel Ramani - Associate Fellow at the Royal United Services Institute and Author of 'Putin's War on Ukraine'.  Marieke De Hoon - Assistant Professor in International Criminal Law at the University of Amsterdam.