WWII, Foo Fighters and UFOs
There does exist an international conspiracy that includes world leaders - past and present - as well as the Vatican who fear the truth as it conflicts with their agendas, teachings, and power. Aliens in any form - including humans as we are not from here - have always been part of the human experiment.
The current insert entered the simulation during WWII with Foo Fighters and other sightings which would take us to Hitler's agendas of biogenetic experiments (as a mirror of our reality) and time travel (time holds the illusion in place) during FDR's administration.
The 2002 TV miniseries Taken by Steven Spielberg gave a very strong chronology of events to that end without mentioning Presidents directly.