IMHO, Ears from the 1800's would suffice. Ears that heard advice such as this, which is as valid today, as it was well before the First World War, then a 2nd world war and now the start of a 3rd.
Imagine a country without guns and gun violence, that is what we could agree on.
"The earth is but one country and mankind its citizens."
"Let not a man glory in this, that he loves his country; let him rather glory in this, that he loves his kind."
"O rulers of the earth! Be reconciled among yourselves, that ye may need no more armaments save in a measure to safeguard your territories and dominions."
"Compose your differences, and reduce your armaments, that the burden of your expenditures may be lightened, and that your minds and hearts may be tranquillized. Heal the dissensions that divide you, and ye will no longer be in need of any armaments except what the protection of your cities and territories demandeth. Fear ye God, and take heed not to outstrip the bounds of moderation, and be numbered among the extravagant.
We have learned that you are increasing your outlay every year, and are laying the burden thereof on your subjects. This, verily, is more than they can bear, and is a grievous injustice. Decide justly between men, and be ye the emblems of justice amongst them. This, if ye judge fairly, is the thing that behoveth you, and beseemeth your station." All from –
Baha’u’llah
Regards Tony