The advancement in technology was hidden from the common society while those who were in the Know capitalized on the Secret Knowledge and formed Secret Space Programs. Every Government and Corporation formed alliances with the Fallen Angel influences that usurped domination over their geographical locations on earth. The Secret programs traded technologies and capabilities between their alliances to enhance their control over their realm of influence.
Not all of the ship designs were viable seeing that these Fallen Angels are in stiff competition between themselves and their galactic war sometimes manifests itself here on earth.
The struggles between political forces within a country and against countries are clear manifestations of these Fallen Angels fighting among themselves.