The Earth Military is Earth's defense force. They are made up of humans and any other species who become citizens of Earth. They defend Earth from invasion and soldiers go through years of training before even becoming a private.
The Earth military was founded in the year 2880. The United Nations agreed to unite all of Earth's militaries to form one military for the planet. They have held off invasions and invaded to preserve justice in the universe. In 2901, species other than humans were allowed into the Earth Military due to the rising threat of the planet Odin.