Unfortunately, since the ad is copyrighted material, I can't quote it in full here. But here are the key passages:
GENERAL PETRAEUS OR GENERAL BETRAY US?
Cooking the Books for the White House
. . . .
Every independent report on the ground situation in Iraq shows that the surge strategy has failed. Yet the General claims a reduction in violence.
The ad then goes on to explain why it believes the General's claim is false.
In evaluating this claim, one needs to be aware that the General has an information advantage over MoveOn.org. That's because the General is in Iraq most of the time, and he has access to up-to-the-minute reports from his troops. MoveOn.org is in the USA and has to make do with second-hand information.
However, if you are going to call someone a liar, you had better have your facts straight. So before making its claim, MoveOn.org had a responsibility to make sure it was correct in its belief that the Surge was not reducing violence.
Today, it is beyond dispute that the Surge did greatly reduce violence in Iraq. To prove this, here are data from two liberal organizations which track civillian casualties there:
Iraq Body Count
Iraq Coalition Casualty Count
Both datasets show that during and shortly after the Surge, civillian casualties dropped dramatically.
Now, you might object that as of September 10, 2007, when the ad appeared, the data were much more ambiguous. And this is true. But . . .
* As of September 10, 2007, the General would have had much better information than the general public.
* As of September 10, 2007, even publically available data (in particular Iraq Body Count data, as they work a bit faster than ICCC) suggested that violence was declining. Here is a September, 2007 Iraq Body Count report which admits as much.
* If you are going to call someone a liar based on incomplete information, you had better be sure that your information is true. If you aren't, you need to either investigate more, or wait for someone else to come up with more complege information, before you make your accusation.
MoveOn called Petraeus a liar based on its own belief of fragmentary and incomplete information about what was happening. And even at the time, a liberal organization with a careful and consistent methodology (namely IBC) had noticed what was really happening.
As of September 10, 2007, it was not crazy to believe that it had not been publically proven that the Surge was reducing violence. But it was crazy to believe that it had been publically proven that the Surge was not reducing violence. And that's what the ad claimed.
The upshot is that Petraeus was right and MoveOn was wrong, pure and simple.