How is public diplomacy (PD) described?

From the text:

Public diplomacy (PD), as a concept, an academic discipline, and a form of professional practice has attracted increased interest in recent years. Defined here as an international actor’s policybased communication activities designed to understand, engage, inform, and influence foreign publics in support of national/institutional interests, PD has now been adopted by governments from around the world and across the political spectrum. Countries ranging from China and Kazakhstan to Israel, Malaysia, and beyond have seized on PD as a key component of their statecraft because it is an exceedingly flexible instrument that can be used to serve a number of different functions.