Freemasonry during World War I
Freemasonry during World War I upheld its universalist principles, yet Freemasons in countries at war served their respective nations without restriction, thereby challenging the Lumières-derived principles of universal fraternity that have governed Freemasonry since its inception. The networks it established before the outbreak of war served to foster hope for a pacifist solution to the global economic tensions that were being experienced at the time.
Source: Wikipedia — Freemasonry during World War I (CC BY-SA 4.0)