Diplomacy is the established method for influencing the decisions and behaviour of foreign governments and peoples through dialogue, negotiation, and other measures short of war or violence. The modern practice of diplomacy grew from post-Renaissance European state system practices and, by the 20th century, had spread worldwide. It encompasses all official diplomatic relations as well as international conferences, summits and other gatherings, parliamentary diplomacy, the diplomatic activities of supranational and subnational entities, and unofficial diplomacy by nongovernmental elements. It also entails the practice of consular diplomacy, which is the work done by consuls to protect the interests of their nation’s citizens abroad and facilitate trade.
In the early modern era, diplomats were generally nobles sent on extended assignments to other states, while embassy staff was comprised of professionals with many more years of foreign experience than their superiors. This helped engender the development of an extensive literature on diplomatic procedure. The 17th and 18th centuries saw significant developments in formalization of diplomatic relations, including the Peace of Westphalia, the first treaty to lay down principles of sovereignty and non-interference, and codification by the Congress of Vienna of protocols governing diplomatic precedence.
In the 21st century, diplomacy has taken on new challenges arising from the globalization of economies and societies. For example, mass migration and refugee flows pose a significant challenge for the maintenance of bilateral relations, and diplomatic efforts are focused on securing humanitarian aid, facilitating migrant resettlement, and addressing the root causes of displacement. Diplomacy is often conducted in a climate of increasing polarization and competition for resources, which can sometimes create a dynamic that leads to tensions and even open conflict. Nevertheless, diplomacy remains vital to the pursuit of global peace and security.