In Jainism, the core vow is ahimsa (non-violence). The ideal is to avoid violence in all circumstances.

What about fighting for dharma?

• It is considered only in the rarest, most unavoidable cases—primarily for self-defense or to protect the lives of others when there is no non-violent alternative.
• Even then, the aim should be to minimize harm and to protect life, not to conquer or kill out of anger or revenge.
• Generally, Jains are urged to use peaceful, non-violent means to uphold right conduct and protect the vulnerable. Violence is not the preferred method to defend dharma.

Important caveats:

• Different Jain traditions (Digambara and Śvetāmbara) may emphasize slightly different nuances in interpretation, but both uphold non-violence as the highest principle.
• When violence is contemplated, it is framed as a last resort, guided by the intention to protect life rather than to aggress or dominate.

If you’d like, I can guide you to authentic Jain sources that discuss ahimsa, self-defense, and the minimal-use-of-force principles in more detail.