OPA and nuclear weapons.
Is it ever mentioned how the OPA got the couple of dozen high yield fusion bombs they were planning to use on Eros surface? It seems odd they have them but don't really work as a deterrent.
I mean, they have ships capable of reaching insane speeds and nukes to load on said ships, even if for whatever reason they don't have the tech to build decent torpedoes, those two things would make a very impressive weapon, but until Inaros all the OPA acts of resistance were pretty tamed.