Those are some pretty vague questions - I'm not an American but has the government ever admitted to imprisoning innocent people in Guantanamo Bay? If they have, would they admit to it and say the torture of these innocent, unlucky people was necessary for the sake of fighting the War on Terror? If they haven't, would they?
In my country, before our recent general election, everything was very much smoke and mirrors to do with the economy. No one knew what was going on and the government were lying; taking back what they said; lying again... text book politics.
But to think a government could hide something like 9/11 being an inside job is phenomenal; hundreds of people (thousands, even) would have to be involved in something like that and there's no way they'd all remain silent.
Your government shouldn't hide anything from the people. It is the people, elected by the people, for the people. Obviously, I understand keeping top secret missions like the Bin Laden operation etc. low scale to make sure it works out, but to not be honest about the economical future or to outright lie to its people is absurd.
America is definitely not the only country that supposedly does this... America doesn't even come close. Just look at Burma's highly-militarised government or Mugabe's Zimbabwe. There's corruption in a lot more countries but these are the two that stick out to me. Pretty sure there are a lot worse examples out there but the media over here reports on these guys the most so they're the ones that come to mind.
'It's been a prevalent notion. Fallen sparks. Fragments of vessels broken at the Creation. And someday, somehow, before the end, a gathering back to home. A messenger from the Kingdom, arriving at the last moment. But I tell you there is no such message, no such home -- only the millions of last moments . . . nothing more. Our history is an aggregate of last moments.'