In the publication UN sanctions: liability or asset in mediation processes?, released by the Centre for Humanitarian Dialogue (HD), Professor Thomas Biersteker, Dr Rebecca Brubaker and Dr David Lanz examine the impact on peacemaking of sanctions imposed by the United Nations (UN). Drawing on observations from cases in Afghanistan, Libya, Sierra Leone, Somalia, South Sudan and Yemen, the authors address five preconceived ideas about those sanctions, namely that they do not work, are inflexible, prevent mediators from talking to sanctioned parties, enable leverage, and imperil mediators’ impartiality.