From the Slog, I shot at the Forged guard, then at the Super Mutants on the bridge, also a Caravan was at the Slog, it all kicked off

Instigating Salisbury Steak!

It's constant in my game. To make matters worse my Provisioner for the Slog seemed to always walk right through Saugus Ironworks...perpetual warfare it seems. Same with Zimonja and that little raider hut. Thank the gaming gods for missile turrets. They pretty much end most of the chaos before it can really get going.