The aim of this thesis is to conduct a comparative analysis of the translation of the six adjectives illegal, illicit, unlawful, safe, secure, and criminal from English into Spanish in United Nations Security Council documents, encompassing both negotiated and non-negotiated texts. This study seeks to examine the influence of the negotiation process within the political-diplomatic context on translation decisions, with particular emphasis on the transfer of connotative, intensifying and semantic nuances. To this end, a corpus comprising resolutions and verbatim records published in 2018, 2021 and 2024 will be compiled, which correspond to the genres of negotiated and non-negotiated documents. A mixed-methods research approach, combining both qualitative and quantitative analyses, will be employed to examine how these nuances have been rendered in the translation process, as well as the procedures used in each translation solution for the six adjectives examined in this study. This will allow for a comparative analysis of the translation trends characterising each textual genre.