The Alliance Military is the armed forces of the Systems Alliance, a coalition of human colonies and planets in the Mass Effect universe. It is responsible for defending human interests and maintaining peace in space. The military includes various branches, such as the Navy and Marine Corps, and utilizes advanced technology and starships for its operations. The Alliance Military plays a crucial role in interstellar conflicts and diplomacy, often collaborating with other species and organizations. Key figures, like Admiral Hackett, lead strategic initiatives, while soldiers and officers are trained to handle diverse threats, including hostile alien species and rogue factions.