Neighborhoods like Muadamiya -- a rebel stronghold on the outskirts of Damascus -- are surrounded by government troops. Residents told us Syrian soldiers are blocking the delivery of all food and medicine. Graffiti warns people to kneel to President Assad or starve.
We reached out to Muadamiya activist Qusai Zakarya on
He told us about an 18-month-old girl, Rana. She was born prematurely and according to Zakarya, died in September when the special baby formula she needed ran out.
"I used to go and see her every couple of days to check on her," he said. "She was so adorable. There's no words to describe what happened to her."
The problem is now spilling across the border.
Even for the families who manage to escape from Syria, childhood malnutrition remains a serious threat. Sanitation in these refugee camps is poor and food is limited.
Linda Shaker Berbari is a nutritionist with a Christian charity in Lebanon, International Orthodox Christian Charities, which works under the umbrella of UNICEF. She and her team comb the camps looking for vulnerable children.
"She's two years old, so she's very small," Berbari said of the child.Berbari's charity is treating more than 80 cases of malnutrition, but she believes there are many more.
"In extreme cases they just -- they have a blank face and no expression," she said. "They even -- in younger ones they just stop crying."
Said Zakarya: "It's something just cannot happen in the 21st century -- to see small kids dying from malnutrition and lack of food while you know that food is only five minutes away behind the Assad checkpoints."
But using hunger as a weapon is as old as war itself -- for the simple reason that it's so effective.