Expert on international summits Professor Tristen Naylor joins Ali and Suzanne to ask what summits are for, whether they are worth it, and what makes them successful (or not).About the hosts:Suzanne Raine is an Affiliate Lecturer at the Centre for Geopolitics at Cambridge University. She served for 24 years in the British Foreign and Commonwealth Office on foreign policy and national security issues, including postings in Poland, Iraq and Pakistan. She specialised in counter-terrorism and was a senior member of the UK government assessment community. She is also a member of the Board of Trustees of the Imperial War Museum and the Royal United Services Institute (RUSI).Ali Ansari is Professor of Iranian History and Founding Director of the Institute for Iranian Studies at the University of St Andrews in the UK. He is also Senior Associate Fellow at the Royal United Services Institute.