I believe I should follow my word. Striking violates my principles.

Would it be ok if you were upfront about the possibility of striking? That seems like a very achievable adaptation.

I think that would be acceptable to me assuming I had assurances I wouldn't be asked to participate or be represented by union actions that would be violent. No threats, no breaking things, no vandalism, etc.

Strikes are generally non violent, and the majority of times that they become violent, it's instigated by strike breakers hired by the company (including police). There is over a hundred years of history of this - plenty for you to read if you want to learn more.