The battle outcome is in your hands, either alone (singleplayer) or with other comrades (multiplayer) you have to defend your main base and secure all resources, and avoid exhausting your reserve forces. To guarantee victory, you first have to destroy the enemy's (Territory Control Center) and replace them with yours which are necessary for having revenue of resources. After capturing all territories, the enemy's main base shield will go down allowing you to strike and destroy them for good.