In 1917, Pope Benedict XV wrote his 'Letter to the leaders of the belligerent nations' in which, emphasising the 'perfect impartiality' that characterised the Holy See's position in the ongoing world conflict, he defined war as a "calamity", a 'veritable suicide', a 'useless slaughter'. In that context, the pontiff stated that even in an attitude of 'absolute impartiality and charity,' the Church had not ceased to 'exhort belligerent peoples and governments to return to brotherhood.' The impartial role of the Holy See was solemnly enshrined in 1929, in Article 24 of the Lateran Treaty, which outlines the position of the Holy See and the Catholic Church as a whole in international relations: "The Holy See, in relation to the sovereignty that belongs to it also in the international field, declares that it wishes to remain and will remain outside temporal competitions between other States and international congresses convened for this purpose, unless the contending parties make a unanimous appeal to its mission of peace, reserving in any case the right to assert its moral and spiritual authority. As a result, Vatican City will always and in all cases be considered neutral and inviolable territory." Over the years, the various popes who have succeeded one another on the Chair of Peter have declined the impartial role of the Church in international conflicts, interpreting it according to their different sensibilities. Similarly, the call for fraternity found fulfilment in the extraordinary document on "Human Fraternity for World Peace and Living Together" signed by Pope Francis and the Grand Imam of Al-Azhar Ahmad Al-Tayyeb in February 2019. This contribution aims to analyse the Catholic Church's commitment to peace, with particular attention to the principle of fraternity, which is absolutely revolutionary in today's international context, seemingly characterised by the principle of strenght.