This handbook integrates a range of conceptual and empirical approaches to diplomacy in the context of ongoing technological and societal change.  Technological and societal disruptions affect modern diplomacy, altering its character and reforming its way.  In light of such changes, this book offers both historical foundations and contemporary perspectives in the field. By doing so, it demonstrates how contemporary change impacts the work of diplomats representing sovereign states. Global diplomatic services will forever be affected by the digitalization of engagement between states during and after the COVID-19 pandemic. In this rapidly changing culture, with burgeoning geopolitical and geostrategic realignment among global powers, the tools of diplomacy have changed.  The state foreign policy astuteness and responses to these changes could have long-term impacts. All this culminates in opportunities for improving the management of diplomaticservices and efficiency of the Ministries of Foreign Affairs (MoFA) of various states.  This book provides useful insights into how modern diplomacy works, especially the integration of informalities into formal diplomatic practices in complex peace and security environments, within such a framework of change.