what language do they speak in the un
And in order to cover the most of other countries, they added the 2 dominant languages of west (Spanish) and east (Arabic). I think if there was a rationale in choosing a language as the official language of UN, only Spanish and Arabic are chosen reasonably as they cover more than 50 countries in the world. I am sure the list of official languages in the UN would be quite different if the victorious countries were different.