A country may designate another country as its “Sworn Enemy” using this law, While a Sworn Enemy is active, your country gains bonus damage when fighting against that specific country in battles.
The damage bonus starts at 1% and increases by +1% per day, up to a maximum of +10%
Enacting this law requires Paper, scaled by your country's average development
Formula:
Total Paper Cost = Base Cost × Average Development
For example, with a base cost of 10 and an average development of 14.56, the total enactment cost is 15 Paper
Countries with the Fanatic Isolationist ethics modify the Sworn Enemy mechanic: