Everyone wants the upper hand in a negotiation, so much so that nations would often dispute the titles of their diplomats in order to appear more powerful by comparison. The Congress of Vienna of 1815 settled the argument y establishing an international system of diplomatic ranks. Members of the military often serve in diplomatic missions. Their diplomatic rank reflects both the assigned responsibilities of the particular appointment and their military rank. It can be challenging to compare ranks because different countries have their own distinct implementations of the international system.
Identify the individual's rank. For military personnel, insignias on their uniforms denote rank. For instance, a bar indicates a lieutenant and a star indicates a general. Diplomats use titles to indicate rank, addressing the ambassador as "Excellency."
Use an online chart to compare military ranks unless, or until, you are familiar with them, because there are different branches of the military and many ranks within each branch. In the United States, there are the Air Force, Army, Coast Guard, Marine Corps and Navy, for example.
Categorise diplomatic ranks by remembering that a career ambassador or career ministers are the highest ranks. In the United States, these are equivalent to four-, three-, two- and one-star generals and flag officers in the military, respectively.
There are several ranks below ambassador and they are, in descending order: minister, minister-counsellor, counsellor, first secretary, second secretary, third secretary, attaché, and assistant attaché. A chargé d'affaires is a title conferred on an individual who takes over the responsibilities of ambassador when the ambassador is not present. In the United States, there are two groups---foreign service officers and foreign service specialists---whose ranks start at FS-1, which corresponds to a full colonel in the military. The lowest rank is FS-9.