I'm not certain. If I join the UN, it seems that I am required to do so (as per UN Resolution 47: Definition of a Fair Trial). I recognize that the jury system can be seen as a check on government power, but government transparancy could also be a check on government power. A judge as finder-of-fact could himself be subject to public surveillance during the commission of his duties.

I might have to decline membership in the UN if I choose to eschew the jury-trial system. Is it just to entrust a citizen's freedom to the measured judgement of twelve people who couldn't get out of jury duty?