Diplomacy
Diplomacy is the skill, practice, or profession of using peaceful means to establish relations between two or more parties or to avoid or resolve hostilities between parties with established relations, or to "serve as a bridge between [two] civilizations." () 

Diplomacy was generally considered to be the field of diplomats. In the Federation, diplomatic credentials were established through an official letter of credence. (; )

The background of Captain Jean-Luc Picard in diplomacy was considered to be extensive. ()

Diplomatic resolutions 
 Cease fire
 Diplomatic immunity
 Diplomatic law
 Diplomatic pressure
 Due process
 Embassy
 Foreign policy
 Mutual defense pact
 Nonaggression pact
 Political asylum
 Treaty

Diplomatic roles 
 Ambassadors
 Ambassador-at-Large
 Consul
 Assistant Counsel
 Diplomat
 High Commissioner
 Commissioner
 Junior adjutant

External link 
 

Law
de:Diplomatie und Recht
fr:Diplomatie et loi
nl:Diplomatie en wet