The Untold Story with Martha McCallum, exclusive interviews with top newsmakers who share their inspiring stories of perseverance, positivity, and more.

Now, here's Martha McCallum.

General David Petraeus told us the incredible story of when his life was saved by his good friend, General Jack Keene.

And this week, General Keene recalls his own untold story.

Back in 2010, he was sent to Afghanistan during the surge under President Obama, where he made close personal friendships with the people we were fighting for.

He learned a lot while he was there about their oppression and day-to-day struggles.

There is one story in particular that was so powerful.

He hasn't shared it publicly until now.

On this particular visit, what I really wanted to focus on in the beginning

of the visit, which normally lasted a couple of weeks, were two units that were involved in the

heaviest fighting we had ever undertaken in Afghanistan since the beginning of the war. One was a

marine unit up in the Sengen District, another was an Army unit in the Argydam Valley. And my first

visit was to the Army unit.

C-130 flight out of Kabul to Kandahar a couple of hours,

Blockhawk helicopter from the Kandahar Airfield,

over to the Argonam Valley, a vehicle convoy taking me down to the lead infantry rifle company that was leading the assault into the southern part of the Argonam Valley, the furthest we had ever been.

Got out of the vehicle there, they organized a foot patrol with a platoon of men, which is 35 to 40 people.

These are infantry soldiers. They do close combat fighting,

the toughest fighting that people do in war, as the Marines were doing up in the Sangon district.

The mission of the patrol was to take me and link up with three tribal chiefs who had been

helping the Americans ever since we arrived

in the valley, at somewhat risk to themselves. So they put me in a Mill of Patrol, a double

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