If you follow the money, the only genuine beneficiaries of 9/11 were the Bush Administration, by way of Presidential popularity, and their major financial backers, comprising weapons makers and oil conglomerates.
Consider the billions of taxpayers' dollars which are now pouring into their pockets and which could never have been justified without the attack upon the Twin Towers.
There is considerable evidence that the invasions of Afghanistan and Iraq were advocated by Republican leaders from before they grabbed the White House - and the only proof of guilt for 9/11 has been allegations by the Administration - still awaiting support by ANY independent inquiry or investigation.
It could be argued that this is all simple coincidence and proves nothing - UNLESS ONE APPLIES THE PRESIDENTIAL CRITERIA THAT ALL SUSPECTED OF INVOLVEMENT IN TERRORISM ARE GUILTY UNTIL PROVEN INNOCENT.
In which case, there is a rock-solid case for removing all leading members of the Administration to Quantanimo Bay for months of questioning in smoke-filled rooms.