St. Petersburg Atrocity
The St. Petersburg Atrocity occurred in 2163, and is considered the proximate cause of the Unification Wars, analogous to the assassination of Franz-Ferdinand and the First World War.
The local hyperclasses had resolved to do the unfathomable: annihilate an entire segment of the city’s population for anti-governmental behavior. While the world was shocked by this, the MSY was further shocked by a subsidiary revelation–that a substantial number of newly contracted girls were dead in the event, not from an accident as originally believed, but due to the deliberate betrayal of members of the MSY’s FA-sympathizing faction.
As a result, the MSY firmly sided with the United Front.