With the end of the 20th century, there was a change in the nature and methods of using military force in international politics. It led to the need to develop new cooperation methods between states and reorient military diplomacy into defence diplomacy. In the new reality, the group of entities influencing diplomatic activities has been expanded to include non-governmental entities, including think tanks. It raised questions about the role of expert centres in activities for defence diplomacy under Polish conditions, including shaping the international situation and shaping the state's defence policy. The following considerations are an attempt to answer this question. The analysis was based on the data obtained from a survey and information from the websites of fifteen Polish centres of expertise operating in international relations, political science, and security and defence.

Defence diplomacy is increasingly important in modern states’ foreign and security policies. The ever-expanding circle of issues of interest fosters the strengthening of the role and importance of defence diplomacy. Alongside the traditional areas of military cooperation based on dialogue and support, other areas of interaction serving international security are becoming more visible. Each state has a different set of instruments at its disposal, and they try to shape defence diplomacy in their own way, taking into account the specificities of their own national interests and the environments in which they operate. Despite their natural differences, there is a common understanding that defence diplomacy can enhance trust and transparency in international relations. Nevertheless, with all the similarities in states or international security organisations, it is not easy to talk about a universal model of defence diplomacy. The wide range of diplomatic instruments allows each state to select and adapt them to the specific situation and the conditions dictated by geopolitics or geo-economics in the relevant international policy areas.