[I]t’s worth noting further that the pope’s wish for Abbas is expressed in the subjunctive mode: “che lei possa essere un angelo della pace.” The level of dubiousness or “unfulfilledness” conveyed by the subjunctive mode in romance languages is something English no longer has a strong equivalent for. A more exact translation of the idea in English would be something like “may it be that you become an angel of peace,” or “let it be that you become an angel of peace.”—from the article
According to the Koran there can only be peace when islam rules over all the people of the world, until then islam is at war with all non-islamic people.