The Earth Defense Alliance (EDA) is an organization that is dedicated to protecting the earth from the Europans. The EDA was founded in 1973.
Carl Sagan used his hush money from the EDA for his Cosmos series and used the Cosmos series to prepare humanity for invasion.
Zackary Lightman discovered the fact that Xavier Lightman was near uncovering the secretive EDA just before he "died" in a sewage plant accident.
The EDA's Latin motto is "Si Vis Pacem Para Bellum" or "If you want peace, prepare for war"
They used the games Terra Firma and Armada to train recruits.