or in a region when a fleet invades. For a naval battle, victory occurs if all the enemy's deployed ships are destroyed or retreat within 72 hours. For an invasion, victory for the attacker includes destroying or forcing all opposing enemy fleets to retreat and destroying all existing enemy airfields within 72 hours. If the attacker fails to do this even if all enemy ships are destroyed within the time limit, the defender still holds onto the territory and the invading fleet retreats back to the region it invaded from. Naval powers The player has the option of playing as one of four major World War II maritime powers: the United Kingdom or United States for the Allies, or Germany or Japan for the Axis. At the start of the game however, the player has the option of choosing allies, enabling the creation of alliances that did not exist such as Germany and the United States for example, to be played for the campaign. Smaller naval powers such as the Royal Australian Navy, the Royal Canadian Navy, and the Regia Marina, are played by either the United Kingdom's Royal Navy or Germany's Kriegsmarine. The Soviet Navy and the French Navy do not appear as naval powers in either scenario. Territory Each power starts out with a certain set of territories depending on whether the campaign starts in 1939 or 1941. Some of the powers control territory that they actually did not at the time. For example, Germany's territory includes Libya and Ethiopia (both under Italian rule), the United States controls territories in the Caribbean Sea and South America (both independent), while the United Kingdom controls Canada and Australia (both Commonwealth). The focus of Campaign mode is to capture enemy territories while defending one's own, reducing the number of ports under enemy control to zero. Territories produce four types of resources: money, iron ore, oil, and aluminum for the power that controls them. Money is used to fund construction of ships and aircraft, and fund R&D of new technologies or ship and aircraft types. Iron ore is used for ship construction, oil is used by ships for movement, and aluminum is used for aircraft construction. Capturing territories thus increases the resources available to a player while denying their use to the enemy. Each power has one home port, to which newly manufactured ships and aircraft are stationed upon completion. During the