Look, I went into journalism to do journalism, not advertising.

Afghanistan would have been difficult enough without Iraq. Iraq made it impossible. The argument that had we just focused on Afghanistan we'd now be okay is persuasive, but it omits the fact that we weren't supposed to get involved in nation-building in Afghanistan.In my new book, I open with a quote from Donald Rumsfeld. In October 2001, he said of Afghanistan: "It's not a quagmire." Ten years later there are 150,000 Western troops there.

A soldier in Iraq said that he wanted to "punch Donald Rumsfeld in the gut, then in the face" or something like that. He wanted me to use his name, but I knew he'd get in trouble, so I didn't. However, I felt it was a great quote because it summed up the frustration of those guys at that moment.

I'm talking to people all of the time. So it hasn't really had a big impact. Access is never my main concern anyway. If you keep digging and making phone calls you can get stories and not have to rely on the good graces of the Pentagon spokesperson. I am not in his good graces.

A state department official once told me this about the role of the president. He said: "We wage war for realist reasons, we justify wars for idealist reasons, and it's the president's job to balance the two." I agree.

Johnny Apple, a New York Times correspondent, wrote a front-page story saying Afghanistan could be a quagmire and he was mocked and derided. What is certainly true is that all sorts of resources that would have been used in Afghanistan were diverted to Iraq. Would those resources have helped? Almost undoubtedly. Whether or not Afghanistan would be a peaceful nation-state had we not gone into Iraq I doubt. Afghanistan is going to be Afghanistan, no matter how hard we try to make it something else.

I want to be the greatest investigative reporter of my generation.