An army with the Purge the Foe Force Disposition facing one with Disruption is dealt Punishment as its primary mission.
The opposing army is not playing the same mission: it is dealt Delaying Action. Reading only your own card is how a game gets lost from in front.
Purge-the-Foe against Disruption. At the start of your turn, condemn one to three enemy units that are on objectives and/or destroyed a friendly unit last turn (or any one enemy unit if none qualify); the mark lasts until the start of your next turn. Any condemned unit leaving the battlefield pays at the end of either player's turn. From the second battle round, non-home control and the objective majority each pay at the end of your Command phase. End of battle pays a large bonus for holding the opponent's home objective.
Primary scoring is capped at 15 victory points in a battle round and 45 across the game.