(Warning: Long post ahead and this is Part 1 of 2 parts...no Cliff's notes available due to the complexity of the subject. This IS a Cliff's Notes level writing and it condenses decades of my reading and contemplation)
1952: At the height of the Cold War, with the Korean War raging and the H-bomb about to come on the scene, a fleet of UFO's flys right over Washington DC into restricted airspace in daylight. They are spotted by people on the ground and also tracked by radar.
F-86's are scrambled to intercept. As they close on the objects, the objects go away. The F-86's return to base. The objects return to the restricted airspace, where once again they are tracked on radar and by eye.
Obviously the Soviets had nothing like that then or even now in 2008. The objects were capable of giving off a radar return as well as being clearly visible in daylight. Hence they were real and since no Earthly tech of the time was capable of producing them, their origin is definitely not from the humans of that time.
No good explanation was given for the event. However what followed is interesting if a person knows something about psywar. The inability to explain something properly can easily be masked by making the subject one of public ridicule and scorn. Up to this point the UFO's, which had emerged into the modern era in World War II when strange balls of light called "foo fighters" were seen following Allied aircraft (it turned out Axis aircraft crew saw them as well), were serious subjects of study as no one knew for sure what was going on but there were grave security concerns both in the World War as well as in the early years of the Cold War, a time in which nuclear devices, rockets and jets were being developed at a rapid pace, with the threat of all-out war quite possible.
The 1947 sighting of saucer-shaped craft by Kenneth Arnold in Washington State led to the term "flying saucer", which caught the public imagination. The first report of an incident at Roswell NM indicated a saucer crash had occurred. In 1948 a F-51 (formerly a P-51) flown by Captain Thomas Mantell, who was stationed in Kentucky, was sent up to check out an UFO. It was reported to be 900 feet across, about the size of a fleet carrier of the US Navy, in width. Mantell's plane crashed and no one knew why. The UFO he went after was definitely there but as to whether it was responsible by a direct act, an accident of turbulence/electrical inteference or Mantell's plane failed due to it's own shortcomings is unknown.
Mutiple sightings of UFO's by people trained to spot objects in the sky were made in New Mexico, where we had the 509th Bombardment Group, which was the one and only outfit trained to drop atomic bombs as well as the White Sands Missile Test Range, where the V-2's captured by the Americans at the end of WW II were being tested. The Soviets had no aircraft capable of penetrating to that particular airspace in use at that time and the flight properties were much different than aviation tech of the time was capable of.
Now that you the reader know the background history of what the government was seeing occur and knowing that the government had no good explanation, in order to avoid panic situations like the one that had happened in 1938 with "The War Of The Worlds" radio broadcast, a disinformation campaign was kicked into gear. The crackpots like George Adamski, who claimed the UFO's were from Venus (now known as an inhospitable planet), had a field day and there are some who believe that government operatives would release a few tidbits of information to these crackpots, who would then extrapolate wild tales involving UFO's. Within a few years, what had been a serious curiosity had become a subject of ridicule.
Yet the UFO's did not go away. Read the book "Incident At Exeter", which was a serious book written by a journalist who wanted to write about what happened in Exeter NH. No sensationalism, just solid investigative journalism. This event took place in 1965. Even though the book was serious and had enough quality witnesses to have won a trial on circumstantial evidence had such a trial taken place, by 1965 the amount of crackpot books had overwhelmed the straightforward books on the subject of UFO's.
Anyone with critical reading skills back at that time could tell the difference between the overblown crazy claims and the real stories that dealt with real events, but since truth often takes a backseat to emotional judgment, there would be little more done for serious study. The one effort by the USAF, Project Blue Book, pretty much put the nail in the coffin as a whitewash as it explained away many sightings rather than focusing on the ones that were most troublesome. The UFO's had been swept under the rug by the two-pronged attack of psywar and obfuscation is what I believe happened.
The UFO's as alien craft are no doubt real. Do they make up the majority source of UFO reports? No. In the Soviet Union during the late 1960's, the citizens were encouraged to report UFO sightings. Plenty of them emerged. There REALLY were UFO's but in this case the UFO's were secret military programs, usually rockets, that were being spotted. Once the reports made the Soviet news reports, someone in the KGB figured out the connection between the UFO reports and the military installations. That led to a clampdown on any more UFO reports lest the information get back to the US since we might possibly be able to conclude where Soviet secret military installations were from these UFO reports.
During the development of stealth tech at Area 51, UFO reports were made frequently. The Pave Blue and F-117 looked like nothing which had ever flown, so with their ops restricted to nighttime in order to not give the game away, "lights in the sky" reports were common. We had very good reason to keep our stealth research secret as it was an overwhelming edge we were developing. Keep enough people in the dark while objects flit about in the dark to see how many good UFO stories were true but the conclusions drawn as to what they were had nothing to do with aliens.
Yet the real alien craft were out there and they showed up quite well in the Mexico City video, trailing a formation of helicopters in the daytime. The modus operandi of US military secret aircraft did not include flying over foreign capitals in broad daylight...LOL! No one else had small silvery roundish objects in their possession on this planet. It doesn't take a rocket scientist to know non-rocket tech in an unfamiliar appearance that had nothing in common with human aircraft to conclude these craft were not of human origin.
I have seen the Aurora program contrails in person in Utah. This craft utilizes a pulse ramjet of some sort and the resulting contrail is one of pulses instead of a steady stream like a turbojet produces. This sighting took place just a few years after the announced retirement of the SR-71 Blackbird. The US government would not give up such a capable platform unless it had a better one in hand. It does and it has since around 1990.
(end part 1)