Cowboy diplomacy

Cowboy Diplomacy refers to a diplomatic effort being made that involves means that are outside normal and acceptable practice.

After meeting Spock on Romulus, Captain Jean-Luc Picard told Spock that the kind of cowboy diplomacy he had engaged in throughout his long history of service to the United Federation of Planets would not so easily be tolerated anymore. Spock responded that he had participated in cowboy diplomacy long before Picard had been born. (TNG episode Unification, Part II]]).

Later, when the Romulan underground arranged for the Vice-Procounsel M'Ret and his two top aides to defect to the Federation. At about the same time, Stefan DeSeve - who had earlier defected to the Romulans had grown disillusioned with Romulan life - decided to return to the Federation. Spock had him relay a message to Jean-Luc Picard, and told him that it involved more cowboy diplomacy, something that Spock said Picard would understand. DeSeve managed to meet with Picard and deliver the message. (TNG episode Face of the Enemy).