Esperanto and international law?

The question of the language in which international legal activity is to be conducted has always been contentious.Why does the UN have only 6 official languages? How were those languages chosen? What does that mean for people who do not speak those languages? Is French still important as a diplomatic language, or is English increasingly the dominant international language?
For a discussion of how the use of Esperanto may avoid some of the unfairness and difficulties associated with the increasing dominance of English in the international sphere, see my contribution to the debate on this topic on Voelkerrechtsblog:

Towards a more radical deterritorialisation of language