30 Only if we desire peace, as we should, instead of war, and only if we all aspire sincerely to fraternal harmony among nations, shall it come to pass that public affairs and public questions are correctly understood and settled to the satisfaction of all. Then shall international conferences seek and reach decisions conducive to the longed-for unity of the whole human family. In the enjoyment of that unity, individual nations will see that their right to liberty is not subject to another's whims but is fully secure.
Source: Ad Petri Cathedram (Vatican.va)