We need to first inspect as to why Lady Fallingstar's understanding of the events, and Terra's don't match up, the details in Terra's tale add some credibility to the Dwarf, but it may be entirely possible that both tales are false and the two are trying to determine who is interfering with them. Stahn does have a glib tongue and a clever mind.
As to causing war, I see no reason why unaffiliated brigands assaulting a tower that has lost it's defenses would cause many immediate instances as long as we avoid the trap of talking to folks that we shouldn't be having discussions with.
I would rather not try to forge alliances at this point, all that will do is tip our hand. Talks at such a level are extremely difficult to conceal and they'd serve to confirm any actions are are taking. Are the dwarves serving as slavers in the Northlunds under King O'Dell's authority, if not what group does he represent? I'm afraid I'm not well versed in dwarven power structures.
I'll reach out to Sam and see if he can confirm the null magic zone, which would more confirm Terra's tale, as well as confirm the source of such locations.
Ultimately concerns about repercussions aside, the Northlunds enslave multiple races, I've spent almost five years, a good portion of time to us shorter lived races, building the resources and framework to be able to begin to sap the strength out of them and free so many Wylderkin and Biata from their grasp, I'm not going to stop, or waste an opportunity now, even as I take pains to minimize the effect.
If a time comes and needs be, let the blame for these attacks be laid upon me for a time, my compassion for at least one of the slave races is well known and I have already been recognized in at least one of the assaults. It would be nice at least if the next time you point to me as the cause for a problem/war that you were at least correct Liddia. Unless you think I've already forgotten about the war with the Dark Dwarves and the accusations I received in those days?
Foss, I'll reach out to Sam, assuming we can confirm the null zone, may I tap you to lead the assault of those with martial skills? I am afraid I myself am busy with another project at the moment and won't be able to pay it personal attention in the time frame we likely have. Understand that my goal at the moment is damaging but limited assaults, do not destroy the tower, the goal is to free those within, for a number of reasons, information being one of them, and cause economic damage without forcing one of the council to become personally engaged. (Remember in their eyes slaves and goods can be replaced.)
-Enan