Why did the Paul Gross character want to call off the killing

It was mentioned, The Ghost (Afghani guy) was wanting to martyr himself. I think he was trying to do so as to unite more Afghani people against the corruption of the bad guy (Who obviously had all those other troops pre planted). Even the bad guy was starting to lower his weapon, understanding how that death would unite the people.
As North Americans and Europeans, we tend to think in quite a linear manner. There are people in other parts of the world that thing in more circular manners. this is why foreign policy is such a quagmire.