Was There a Post Nine 11 Cover Up by the US?

The government keeps lots of things to itself, and doesn't reveal everything it knows about what happened in a crisis like 9/11. The information could be embarrassing to the us or its allies. There is evidence that pakistani intelligence was in bed with alcida and may have been aware of the attacks. And our government didn't choose to mention that because we really needed pakistan as an ally in the war on terror.