Everyone at the public high school in Aziziya knows that the senior boys may soon be drafted into President Bashar al-Assad’s army to take up the fight in the country’s escalating civil war.

When FRONTLINE’s Olly Lambert — the first Western filmmaker to spend an extended period of time living on both sides of the war — visited, students erupted into a spontaneous demonstration in support of the Syrian regime. “God, Syria, Bashar and nothing else,” they chant in this clip from tonight’s film, Syria Behind the Lines.

The villagers of Aziziya are nearly all Alawite, a religious sect whose faith is loosely rooted in Shia Islam, and almost all of them support the government. Many Alawites believe that the fall of the regime would lead to their death at the hands of the rebels.

For generations, Aziziya’s Alawites had lived peacefully with the Sunnis in the Orontes River valley — even during the first year of the Syrian uprising. But as the revolution entered its second year, neighboring Sunnis began weekly demonstrations calling for the overthrow of President Assad and his regime. Today, the valley is deeply divided.

Syria Behind the Lines airs tonight on PBS. (Check your local listings.)