My very identity as a soldier came to an abrupt end. I'd been soldiering as long as I'd been shaving. Suddenly I'd been told I could no longer soldier, and it felt as though no one really cared if I ever shaved again.

If every soldier is authorized to make one mistake, then we lose the war.

If you talk to a British officer or NCO about the strategic objectives of the end state, you'll often get a spirited discussion that's very well informed.

In June 2010, after more than 38 years in uniform, in the midst of commanding a 46-nation coalition in a complex war in Afghanistan, my world changed suddenly - and profoundly. An article in 'Rolling Stone' magazine depicting me, and people I admired, in a manner that felt as unfamiliar as it was unfair, ignited a firestorm.

I find that if the day is terrible but I worked out, at the end of the day I can go, 'Well, I had a good workout'. Almost no matter what happens.

Throughout history, the organizational evolution of the military has been inextricably linked with that of the business world.