The tiny pill fueling Syria’s war and turning fighters into superhuman soldiers….

Captagon pills are displayed along with a cup containing cocaine at an office of the Lebanese Internal Security Forces, Anti-Narcotics Division, in Beirut in 2010. (Joseph Eid/AFP/Getty Images/File)

As The Post’s Liz Sly recently noted, the war in Syria has become a tangled web of conflict dominated by “al-Qaeda veterans, hardened Iraqi insurgents, Arab jihadist ideologues and Western volunteers.”

On the surface, those competing actors are fueled by an overlapping mixture of ideologies and political agendas.

Just below it, experts suspect, they’re powered by something else: Captagon.

A tiny, highly addictive pill produced in Syria and widely available across the Middle East, its illegal sale funnels hundreds of millions of dollars back into the war-torn country’s black-market economy each year, likely giving militias access to new arms, fighters and the ability to keep the conflict boiling,according to the Guardian.

“Syria is a tremendous problem in that it’s a collapsed security sector, because of its porous borders, because of the presence of so many criminal elements and organized networks,” the U.N. Office on Drugs and Crime (UNDOC) regional representative, Masood Karimipour, told Voice of America. “There’s a great deal of trafficking being done of all sorts of illicit goods — guns, drugs, money, people. But what is being manufactured there and who is doing the manufacturing, that’s not something we have visibility into from a distance.”

A powerful amphetamine tablet based on the original synthetic drug known as “fenethylline,” Captagon quickly produces a euphoric intensity in users, allowing Syria’s fighters to stay up for days, killing with a numb, reckless abandon.

“You can’t sleep or even close your eyes, forget about it,” said a Lebanese user, one of three who appeared on camera without their names for a BBC Arabic documentary that aired in September. “And whatever you take to stop it, nothing can stop it.”

“I felt like I own the world high,” another user said. “Like I have power nobody has. A really nice feeling.”

“There was no fear anymore after I took Captagon,” a third man added.

According to a Reuters report published in 2014, the war has turned Syria into a “major” amphetamines producer — and consumer.

“Syrian government forces and rebel groups each say the other uses Captagon to endure protracted engagements without sleep, while clinicians say ordinary Syrians are increasingly experimenting with the pills, which sell for between $5 and $20,” Reuters reported.

Captagon has been around in the West since the 1960s, when it was given to people suffering from hyperactivity, narcolepsy and depression, according to the Reuters report. By the 1980s, according to Reuters, the drug’s addictive power led most countries to ban its use.

The United State classified fenethylline (“commonly known by the trademark name Captagon”) as a Schedule I drug under the federal Controlled Substances Act in 1981, according to the National Criminal Justice Reference Service

Still, the drug didn’t exactly disappear.

VOA notes that while Westerners have speculated that the drug is being used by Islamic State fighters, the biggest consumer has for years been Saudi Arabia. In 2010, a third of the world’s supply — about seven tons — ended up in Saudi Arabia, according to Reuters. VOA estimated that as many as 40,000 to 50,000 Saudis go through drug treatment each year.

“My theory is that Captagon still retains the veneer of medical respectability,” Justin Thomas, an assistant professor of psychology and psychotherapy at the UAE’s Zayed University and author of “Psychological Well-Being in the Gulf States,” told VOA in 2010. “It may not be viewed as a drug or narcotic because it is not associated with smoking or injecting.”

Five years later, production of Captagon has taken root in Syria — long a heavily trafficked thoroughfare for drugs journeying from Europe to the Gulf States — and it has begun to blossom.

“The breakdown of state infrastructure, weakening of borders and proliferation of armed groups during the … battle for control of Syria, has transformed the country from a stopover into a major production site,” Reuters reported.

“Production in Lebanon’s Bekaa valley – a traditional centre for the drug – fell 90% last year from 2011, with the decline largely attributed to production inside Syria,” the Guardian noted.

Cheap and easy to produce using legal materials, the drug can be purchased for less than $20 a tablet and is popular among those Syrian fighters who don’t follow strict interpretations of Islamic law, according to the Guardian.

Doctors report that the drug has dangerous side effects, including psychosis and brain damage, according to the BBC.

Ramzi Haddad, a Lebanese psychiatrist, told Reuters that the drug produces the typical effects of a stimulant.

“You’re talkative, you don’t sleep, you don’t eat, you’re energetic,” he said.

According to the news service:

A drug control officer in the central city of Homs told Reuters he had observed the effects of Captagon on protesters and fighters held for questioning.

“We would beat them, and they wouldn’t feel the pain. Many of them would laugh while we were dealing them heavy blows,” he said. “We would leave the prisoners for about 48 hours without questioning them while the effects of Captagon wore off, and then interrogation would become easier.”

One secular ex-Syrian fighter who spoke to the BBC said the drug is tailor-made for the battlefield because of its ability to give soldiers superhuman energy and courage:

“So the brigade leader came and told us, ‘this pill gives you energy, try it,’ ” he said. “So we took it the first time. We felt physically fit. And if there were 10 people in front of you, you could catch them and kill them. You’re awake all the time. You don’t have any problems, you don’t even think about sleeping, you don’t think to leave the checkpoint. It gives you great courage and power. If the leader told you to go break into a military barracks, I will break in with a brave heart and without any feeling of fear at all — you’re not even tired.”

Another ex-fighter told the BBC that his 350-person brigade took the pill without knowing if it was a drug or medicine for energy.

“Some people became addicted to it and it will damage the addicts,” he said. “This is the problem.”

Roman-era shipwreck reveals ancient medical secrets….

A first-aid kit found on a 2,000-year-old shipwreck has provided a remarkable insight into the medicines concocted by ancient physicians to cure sailors of dysentery and other ailments.

A wooden chest discovered on board the vessel contained pills made of ground-up vegetables, herbs and plants such as celery, onions, carrots, cabbage, alfalfa and chestnuts – all ingredients referred to in classical medical texts.

The tablets, which were so well sealed that they miraculously survived being under water for more than two millennia, also contain extracts of parsley, nasturtium, radish, yarrow and hibiscus.

They were found in 136 tin-lined wooden vials on a 50ft-long trading ship which was wrecked around 130 BC off the coast of Tuscany. Scientists believe they would have been used to treat gastrointestinal complaints suffered by sailors such as dysentery and diarrhoea.

“It’s a spectacular find. They were very well sealed,” Dr Alain Touwaide, from the Smithsonian Conservation Biology Institute in Washington DC, told The Sunday Telegraph. “The plants and vegetables were probably crushed with a mortar and pestle – we could still see the fibres in the tablets. They also contained clay, which even today is used to treat gastrointestinal problems.”

The pills are the oldest known archaeological remains of ancient pharmaceuticals. They would have been taken with a mouthful of wine or water, or may have been dissolved and smeared on the skin to treat inflammation and cuts.