Each cluster has a Ceasefire token, which shows whether its systems are at War or at Peace. The Peace side, shown to the right, limits harm as follows.
To harm anything in a cluster at Peace except Loyal pieces and Blight, you must spend 1 Weapon. If you do, flip the Ceasefire token in the cluster to War.
Harm means battle, hit, damage, or destroy. It doesn't count Crises.
Ceasefires cannot be removed. They track the states of clusters and are only placed in gates for convenience.
Act: 3
A: It would cost 2 weapons: One to apply Battle to the Action Card via the standard Prelude ability of a Weapon, and one to flip the Ceasefire token. It is also one Weapon per flip.