5 Therefore, let all those responsible bring about the necessary conditions for the laying down of arms before the possibility of doing so is taken away by the pressure of events. Those in whose hands rests the safety of the human race should realize that in this day and age they have a very grave obligation in conscience. Mindful of their own nation, of the world, of God and history, let them examine their own consciences. Let them realize that in the future their names will be blessed if they wisely succeed in complying with this exhortation.
Source: Christi Matri (Vatican.va)