The burden of proof is on truthers. People can cite PNAC and every other document they want to dredge up, but at the end of the day, pretty much everything has been debunked or not stood up to scrutiny.
The 9/11 skeptics really really make me mad, not because I have any faith in my government or official reports or any of that condescending nonsense people try to lay on you. The real reason is because there have been real, active incredible conspiracies perpetrated by government, corporations and arms of law enforcement or the intelligence community and not 1/10th of the zeal people devote to discrediting 9/11 is utilized.
People want conspiracy? Look at the urban renewal policies that ghettoized black America, look to the Iran/Contra affair under suddenly sainted Reagan, look to the "evidence gathering" in the lead up to the Iraq war, look at how both Bush and Obama let the banks get away with the biggest heist perpetrated on American wealth in a century or look at the quiet deregulation scheme that led to it perpetrated under Clinton, look at what we did to destabilize Mercosur as an alternative South American trading block, look at our "collateral damage" in Yemen and Pakistan, look at the invasion and decimation of Panama, look at the union busting being funded by the Kochs in Wisconsin via their creature Scott Walker, look at the changes in education that are enriching an apparatus of testing companies, consultants and charter organizations, look at the critical services being cut or diluted during engineered government shutdowns and obstructions, look at the money that has poured into lobbying to prevent any real and lasting environmental action.
These are all things that cost lives or make lives worse on a much more massive scale than 9/11 ever did, but because they stretch beyond a climactic single day they seem to be more than the collective minds of truthers can contain.