"I have already made my peace with God because this war is different, it's not conventional," the 23-year-old bespectacled Chicago native says.
"These Taliban have learned their lesson. They adapt as fast as we do, but we are bound by our strict rules. They are not," he adds, panting after a 100-metre dash for cover behind an abandoned mud house.
"It can be a death run like this every day."