U.S. commander: More troops are needed. Surprise. Throughout history, just about ALL commanders say that they need more troops. In this case, I believe that he is referring to more Afghan units, although I am certain that he would accept more U.S. soldiers. (Note - General Grant was one of the few exceptions to this general rule as he cut back on the artillery the army of the Potomac brought with it when it engaged the Army of Northern Virginia in 1864. He believed that too much would hinder his movements, as was subsequently shown.)
Even if everything else were the same, just the terrain alone would require far more troops per capita in Afghanistan than Iraq. Everything else is not the same and in many cases aggravates the need for more units, both combat and support. I doubt that we will obtain anywhere near the same level of support from the Afghan population that we obtained in Iraq, although this is yet to be determined.
The ‘surge’ required the better part of a full year before it became obvious that we were making positive progress. I expect Afghanistan to take longer, although I am not so certain that the outcome will be as decisive as the result was in Iraq.