Best friends, they grew up together. When rebels attacked, they fought together. Eighteen years old and without a day of military training, they picked up Kalashnikovs and went to defend the front line in Yemen’s southern city of Aden.

It was a rite of passage for Osama Ahmed and Ahmed Saleh, a moment for the teens to prove their manhood in a society where every man has a gun and is expected to know how to use it. The day he left for battle, Osama said his mother told him, “Son, I worry about you and want you near me. But if every mother thinks this way, no one will go and fight for us ... Do not leave your friends.”

The 2015 Battle for Aden turned out to be a brutal, scarring experience. Today, three years later, Osama and Ahmed wander a shattered city, disillusioned. They have no jobs, hopes or prospects. Nights, they sit on the beach and watch the moon on the waves of the Arabian Sea, chewing qat _ a narcotic leaf _ and dreaming of leaving Yemen.

In this Feb. 18, 2018 photo, 21-year olds and best friends Osama Ahmed, center, and Ahmed Saleh, who both fought during the '2015 battle of Aden' look at their mobile phones as they chew Qat on the beach, in Aden, Yemen. (AP Photo/Nariman El-Mofty)

“My friends and I, all we think about these days is how to get out,” Osama said. “It doesn’t feel like it will get any better in our lifetime.”

Yemen’s civil war has chewed up and spat out a generation of youth. Fighters on all sides are often minors, some as young as 12, dragged into what many see as a cynical fight between Iranian-backed rebels known as Houthis and a U.S.-backed coalition led by Saudi Arabia nominally supporting the government. Three years of war with no end in sight has wrecked Yemen, causing death, displacement, economic collapse, hunger and disease.

The Battle of Aden began in March 2015, when the Houthis, who overran the north the previous year, stormed south and attacked Aden, the last bastion of the government of President Abed Rabbo Mansour Hadi.

For Osama, Ahmed and their friends, it wasn’t a fight for Hadi, it was for the south against the north; southern Yemen was once independent and separatist sentiment remains powerful. So they joined other volunteers, militiamen and pro-Hadi army units to battle the rebels.

*The Associated Press reported this story with a grant from the Pulitzer Center on Crisis Reporting.*

They took positions in Khormaksar, a neighborhood blocking the way to the heart of Aden, which stands at the end of a peninsula offshore. There were 14 in Osama’s group, armed with seven automatic rifles that they rotated among themselves.

They and the others stood little chance. Rebels blasted them with tanks and artillery and snipers. For weeks, the defenders were pushed back neighborhood by neighborhood into the dead end of the peninsula. It was vicious urban fighting. Osama and Ahmed saw friends blown apart by rockets and mines, along with women and children. They sweltered in summer heat, thirsty and despairing.

Finally, rescue came. Saudi Arabia and its Arab allies launched their campaign of airstrikes and sent weapons, money and training to pro-Hadi fighters. With their backing, fighters were able to drive back the rebels.

In this Feb. 10, 2018 photo, a boy sits in a damages car due to the on-going three year conflict in Mocha, Yemen. (AP Photo/Nariman El-Mofty)

Fighting has since moved to provinces north of Aden. But the city has only further fallen apart.

Militias pervade Aden and, as they multiply, corruption has proliferated. The United Arab Emirates has taken advantage of the fight and now dominates the south, squeezing out its ostensive ally, Hadi. Over the past year, open warfare has broken out in Aden’s streets between pro-UAE and pro-Hadi militias.

To Osama and Ahmed, any veneer of a patriotic fight is gone; all they see is greed and self-interest. “We had hopes and dreams,” Osama said. “(But) we’ve realized that everyone is running toward power and fame.”

“It’s a war over money,” Ahmed said. For everyone else, “there are no salaries, no food, no water.”

The most reliable employment is as a fighter in one of the militias, flush with funds from their international patrons. Otherwise, jobless men hang around all day in the streets.

Mohammed Abu Hassan, a 30-year-old who also fought in the Battle of Aden, can’t bear to look at a weapon.

“Everyone is killing everyone,” he said. “What did we gain out of all this? Nothing.”