If the reports of official meetings between world governments and extraterrestrials in the 1950s and 1960s are to be believed it would appear that world governments asked for and received time to acclimate their respective populations to extraterrestrial reality.
http://galactic.no/rune/usa_et.html In the United States according to documents at http://www.majesticdocuments.com/ the CIA was granted overall authority by the Executive Branch in matters dealing with the public and extraterrestrial realities. I believe part of the CIA's mandate was to develop and implement an acclamation program to prepare the public for direct extraterrestrial contact.