Because the methodology in the first study cannot be verified and thus the numbers cannot be verified. If you have a study, and you dont give out the logic and data you use, then nobody should believe it. The foundation of science is that you should be able to replicate and get the same outcomes. That should be pretty obvious.
Your claim was that X amount of people died because of US forces. The number you gave came from only one source that was discredited. What else is there to say?
No.
The New England Journal of Medicine did a far larger study and found far less deaths than your Lancet study. The NEJM study found less deaths by a factor of 4. That is huge. So you have a bunch of researchers question their numbers. You also have AAPOR question the data and the ASA backing them up. Even if you dont think the AAPOR is meaningful then you should at least be able to say that the ASA backing them is important.
Again, I have facts, and all you have done is try to discredit me instead of arguments and data.
If anyone wants to look at the data, here is the NEJM's own research.
http://www.nejm.org/doi/full/10.1056/NEJMsa0707782#t=article