Players may respond to Pacification Arrayâ€™s ability by activating an ability of the target permanent if that abilityâ€™s timing permissions allow it. Players may also respond by activating abilities or casting spells whose costs include tapping the target permanent.
Once a player has activated an ability with in its cost, Pacification Array canâ€™t be used to undo or counter that ability.
If you want to stop someone from attacking with a creature by using Pacification Arrayâ€™s ability, you must do so before attackers are declared. You canâ€™t wait until after attackers are declared and then try to use it to make a creature stop attacking. Note that your opponent canâ€™t start declaring attackers without letting you use your Pacification Array.