In Countryballs at War, the key to success lies in mastering the delicate art of diplomacy. Forge alliances, send cooperation requests, sign peace treaties, and puppet weaker nations to enhance your power. A limited number of diplomacy and attack points govern each turn — use them wisely to expand your territory, sway rivals, or build formidable armies. Unlock unique units from the barracks and artillery depot, invest in upgrades, and adapt your strategy as new units are introduced over time.