With a tent and some timber, in less than two hours they transformed a vacant lot into a makeshift school -- ready for the children of Marjah to get their first taste of a classroom education, reports CBS News correspondent Mandy Clark.
The first day of school comes the next day, and all the desks are taken. There are even a few girls, in the back row. The question is: How many of these kids will come back to class next week?
These Marines fought hard to take Marjah. They've seen 10 of their own killed here. Now they're on a new offensive -- a charm offensive.
Battalion commander Lt. Col. Brian Christmas spends much of his time walking the streets -- no helmet, no body armor -- reaching out to the people of Marjah, one at a time if that's what it takes.
He sits on the dusty floors with the village elders, trying to inspire them to stand up for themselves.
"If you have three Taliban who come into a village and only one man stands up, you're right, he's probably going to get shot by the Taliban, because the Taliban is only brave against one," Christmas said. "But the Taliban will not be brave against 40."
But Marjah is still a Taliban town. Many of the men gathered around are hardcore Taliban supporters, here to make sure no one speaks too freely.
"If we talk to the Americans, the Taliban will be waiting for us," an elder said. "The Marines can't protect us from them."
About a month ago, a 9-year-old boy was walking home from school and the Taliban grabbed him, beat him and left him tied up. Now the elders are telling the Marines that no one wants to go to school.
By now much of the civilian government should have been in Afghan hands, but the Marines are having a hard time getting local officials to step up and take over.
The Marines organized a ceremony to celebrate the signing of a contract for rebuilding the school.
But Christmas couldn't find the Afghan official who was supposed to lead the ceremony. He hid inside the school, refusing to go outside and stand shoulder-to-shoulder with the Americans.
"You have to be a leader for those children," Christmas said.
Finally, the official came out and signed the contract. It's a forced celebration, but Christmas is stubbornly upbeat.
"For 30 years they've had good reason to doubt. So we're showing them that doubt and that fear can go away and we're well on our way, but it takes patience and time," Christmas said.
Everything these Marines do is designed to send a clear message that they will be here for as long as it takes. The problem is, no one - not even the Marines - knows how long that will be.