The conspiracy I actually give some credence to is not on the list.
That is:
Both the U.S. and the Soviet Union (during the Cold War).deliberately covered up a number of violent encounters (mainly at sea) in order to avoid calls for war
For example I do believe that K-129 did sink either as a result of an attempt to launch a nuclear missile at Pearl Harbor or because of a collision with a U.S. nuclear sub.
I believe that months later the Soviets sank the U.S.S. Scorpion in retailation.
I believe that during 1950 the U.S. Navy sank a Soviet submarine in Korean waters during the early days of the Korean War.
And I believe that the actual number of exchanges of fire between U.S./allied aircraft and Soviet aircraft was far greater than has been admitted.
That is not too hard to believe since it has real world involvement anyone can understand. During the height of the Cold War i can see that some diehard, gung ho commanders may have taken it a bit too far and through either accident or foolishness caused damage to the other side.. both countries knew they don't want to go to war with each other and so they agreed to cover it up so no one gets forced into a war.
Personally i have two conspiracies i believe:
- The JFK assassination.. so much went wrong that day and later. No professional sniper (and Oswalt was anything but a good marksman) could pull off that shot from where he was with that equipment, then evidence got lost and video evidence point to a totally different shooting place that from where Oswalt was standing.
As to who and why JFK was assassinated.. who knows? Maybe it will never been known with so much evidence lost but something is fishy about the whole thing.
- Government are keeping the knowledge about UFOs and Aliens
Personally i believe there is intelligent life out there.. it is inevitable given the vast scope of the universe and even if the chance of life developing on a suitable planet is 1 in a billion and of that to get to sentient life is again 1 in a billion the universe is big enough to make that a possibility. Then there is so much that we don't understand about the physics of the universe.
Einstein has postulated that matter can't travel faster than light and to date that formula stands and couldn't have been disproven but then again take someone from the stone age or before and tell him that man is going to set foot on the Moon and he will not believe. Who knows what feat of engineering and science are needed to make FTL travel possible? Humanity has barely existed in the scope of the universe or even Earth itself and just see at which frantic pace technology and knowledge evolves so i can't rule out that travel between stars will be possible at some point in the future.
So this brings me to the conclusion that aliens might visit Earth but for whatever reason have not decided to do so publicly.. it could be that they were intelligent enough to realize we'd panic and tear us apart in riots and mass hysteria and so they elected to contact the major governments and make themselves known. Maybe there is a long term plan to get this public, maybe there isn't but i believe the world would devolve into mass hysteria at first and it would take quite a while to calm everyone down. This could be why governments are keeping it from us because they believe that our whole social construct would be torn apart and they don't know what would emerge from that and that uncertainty is not that they would gamble with.