Afternoon,this is getting interesting, This Larry Warren fella been messed with for sure. Something happened out there, I seem to remember reading other accounts of this. I want to say one account had to do with nukes being deactivated, and maybe another suggesting the ufo's were shot down with a fancy cool weapon not for general use in the population? Some more from Georgina Bruni's You Can't Tell the People The Cover Up of Britain's Roswell...

..The witnesses, having been seated in front of a movie screen, were again told by Major Zickler that they would be debriefed and to be sure to give their full cooperation. Zickler then departed and three men in civilian suits entered the room. One was introduced as an officer from Naval Intelligence and the other two men represented the Armed Forces Security Service. After the introductions the naval commander gave them a briefing about UFOs and how the government had been aware of them for a very long time. The airmen were told that numerous ‘off-earth’ civilizations visited the planet from time to time, and that some had a permanent presence here. They were then instructed not to discuss any aspects of the incident with anyone on the base and if pressed they should just mention they saw lights in the trees. The commander then gave them a pep talk on patriotism before showing them a film, which revolved around the military’s encounters with UFOs. According to Larry, the footage consisted of segments from various eras, beginning with World War Two, the Korean War and Vietnam, followed by footage from the US space missions. He claims that it was during this meeting that the men were told their security clearance had been upgraded. Having received no further confirmation, written or otherwise, he was of the opinion that the latter was mentioned only as a ploy to deter the witnesses from discussing the incident.

During a conversation I had with Malcolm Zickler, he confirmed that such a meeting had taken place although he did not offer any details. If you have a problem believing that the USAF educate their personnel on UFO matters, let me relate a similar story that was told to me in early 1997. Bruce Taylor, a Vietnam veteran who resides in Seattle, USA, informed me that before going off to war he and other personnel were summoned to a classroom where they were taught what to do in case they came into close contact with a ‘craft of unknown origin’. In the likelihood of an encounter, they were expected to back away whilst observing everything possible, and then report it to their immediate supervisor. Taylor was also shown footage of UFOs in Korea and Vietnam, probably the exact same film that Larry and the other witnesses were shown. Taylor explained how the Air Force deals with this particular subject. ‘What was hard for me was that on one hand they were telling me UFOs don’t exist, but on the other hand they were telling me what to do if I see one.’ I asked him if he had been given any information on extraterrestrials and what they might look like. ‘No, they didn’t tell me what they might look like because that might be too easy,’ he said. He added, ‘I believe there are a couple of different races that fly these craft and I don’t think it would be easy for the governments of the world to tell people what they look like if they are telling everyone that they don’t exist.’
https://exploringrealhistory.blogspot.com/2022/04/part-3-you-cant-tell-people-cover-up-of.html