John 3:16 reads 'MAY not perish but may have eternal life' in Gk. That implies our choice. Many in WW1 did not choose because the international cartel of arms merchants had ignited an arms race in the decades before WW1. Which firms colluded in this? Armstrong, Vickers in UK colluded with Krupp and others in Germany, Schneider in France and even US steel firms. Check books on Zaharoff. It bribed/ controlled governments through share-holdings. This global cartel aimed at commercial profits. Because it was secret, it was a major factor in disillusioning soldiers and others from any belief in God and even in country and politicians.
Were the four empires (Prussian, Russian, Habsburg and Ottoman) all destroyed by a bullet to a grand-duke at Sarajevo or as you suggest, something more devilish? Take the attributes of greed and pride as examples. In the period from 1900 on, a cartel of arms manufacturers exchanged patents on war machines and equipment to make sure that an international arms race was fired up. They persuaded one nation to buy iron-clad warships for example while another arms maker created a shell that would penetrate it. Another then created amor plate to resist the first shell etc. Zaharoff, considered the richest man of this time, first sold a submarine to Greece as a wonder weapon (to end the Turkish threat) and then sold two to Turkey and then negotiated for even more to Russia. Who was in the international cartel? Armstrong, Vickers of UK, Krupp of Germany, Schneider of France, Bethlehem Steel of USA, plus Russian and Japanese firms! They met easily as they had joint stock in a US firm. These firms had great influence on or controlled banks and the most powerful media. They had close interests in the intelligence services. Sounds familiar with any events today?
You are quite right to say that Pax Romana was in fact a period of oppression and in fact almost continuous wars. You ask: Is that the high water mark of peace, the best we can hope to achieve?
If you check a reference like Langer's "Encyclopedia of World History" that we used at Ambassador, it can be proven that Europe hardly had any peace lasting more than a few decades at any time for more than 2000 years. That is until the postwar period. The European Community which was based on some biblical principles by Robert Schuman (Prime Minister of France 1947-8) broke all records. Europeans are now living in the longest period of peace in their entire written history. The area occupied by Israelite tribes now has 'peace and security' for the first time.
My best wishes to you and Bev in this new stage of your Christian service. May the Eternal God be with you in your work.