The Journal of Diplomatic Language is announced for September. It looks promising, but comes at a price:

bq. The JOURNAL OF DIPLOMATIC LANGUAGE, (ISSN 1550-607X) an academic journal appearing four times a year, addresses the power of language in international relations. JDL features peer-reviewed, theoretically grounded reports of research, and provides a forum for in-depth discussion of central issues in diplomatic language. Areas of interest include:
textual analysis of international instruments,
rhetoric, ambiguity, and metaphoric language,
text interpretation and translation,
documentation and archiving,
conceptual and relational analysis,
cultural, social, and historical analysis,
negotiations and travaux préparatoires,
current research methodologies, and
any other topic clearly relevant to the language of diplomacy.