The Goverment works for themselves not for us.
It feels the need to protect us from others and...ourselves.
Sacrifice the few for the greater good of the many as they say.
They'll feed out certain truths in small doses to the media so we can be satisified and go about our normal lives.
If they told the whole truth, there'd be mass paranoia and revolts anyway.
Therefore you will never know 100% truth, because that truth in their opinion is on a 'need to know basis, and we dont need to know'.
You do know there are uncovered documents from the 60's about a plan to frame Cuba to make it look like they were going to attack us; in other words fuel to start a Cuban war? Obviously it never panned out, but the orders were there clear on paper.
So it just goes to show you our goverment isnt always run by honest boy scouts...