Military attaché
A defense attaché (DA) is a member of the armed forces who serves in an embassy as a representative of his/her country’s defense establishment abroad and in this capacity enjoys diplomatic status and immunity. DA is a generic term that covers personnel from all branches of the armed services. However, some larger countries may appoint an attaché to represent an individual service branch, such as an air force or naval attaché [Geneva Centre for Security Sector Governance, p.1].
A military attaché is a military expert attached to a diplomatic mission, often an embassy. This type of attaché post is normally filled by a high-ranking military officer, who retains a commission while serving with an embassy. Opportunities sometimes arise for service in the field with military forces of another sovereign state. The attaché has the privileges of a foreign diplomat [Political Science Quarterly].
The main feature of defense diplomacy is the combined use of diplomatic and military tools. Defense diplomacy activities include: providing military advice and assistance to countries reforming their defense sectors, establishing mixed civilian and military missions in conflict and post-conflict theaters, developing new arms control, disarmament, and security- and confidence-building measures, also mainly in response to the demands of conflict and post-conflict theaters [Geneva Centre for Security Sector Governance, p.2].
Geneva Centre for the Democratic Control of Armed Forces (DCAF). (2007). Defense attachés. Geneva Centre for Security Sector Governance. Retrieved from: https://www.files.ethz.ch/isn/38583/dcaf-backgrounder-defence-attaches.pdf
Craig, G. A. (1949). Military diplomats in the Prussian and German service: the attachés, 1816-1914. Political Science Quarterly.