In 1522, on May 16th to be precise, Zwingli published his ‘anti-war’ book Ein göttlich vermanung an die ersamen, wysen, eerenvesten, eltisten Eydgnossen zü Schwytz, das sy sich vor frömden herren hütind und entladind, Huldrichi Zwinglii, einvaltigen verkünders des euangelii Christi Jhesu and in it he writes, towards the beginning while describing the source of conflict-
How does it happen that we Christians who are united by such powerful agencies have much greater quarrels than unbelievers? And how does it happen that in a Confederacy in which until now a fraternal love prevailed, for the sake of foreign lords violent quarrel has arisen? Answer: Real piety, by which is meant true worship and prayer to God, has disappeared among us, as St. Paul writes to the Romans [Rom. 1:28–31]: “And even as they did not like to retain God in their knowledge, God gave them over to a reprobate mind, to do those things which are not convenient; being filled with all unrighteousness, fornication, wickedness, covetousness, maliciousness; full of envy, murder, debate, deceit, malignity; whisperers, backbiters, haters of God, despiteful, proud, boasters, inventors of evil things, disobedient to parents, without understanding, covenant-breakers, without natural affection, implacable, unmerciful.” From these words of Paul we learn that all these evils which he enumerates arise when we desert God, do not fully recognise Him, do not look up to Him, do not place our whole trust in him, but on the contrary despise Him and regard him somewhat as we would an old sleeping dog.
War comes when God is forgotten! That’s Zwingli’s stunning observation. I recommend that you get hold of the book and read it. It’s fantastic and indeed the editor of the English edition of Zwingli’s works writes in the introductory preface
… what [Zwingli] says about war is worthy of republication by our Peace Societies, and they are entirely at liberty to use this translation.*
The combatants in Israel and Gaza (and in other conflicts around the world) may think that they are doing something grand and good and great and helpful but war is never any of those things. War is atheism and those who perpetrate it are, practically speaking, atheists because war is rejection of and denial of God.
*The Latin Works and The Correspondence of Huldreich Zwingli: Together with Selections from His German Works, Volume 1 (S. M. Jackson, Ed.), p.130.