KAREN STATE, Burma — When an American soldier retires from action, he or she usually opts for a quiet life — a nice house, maybe by the sea, a chance to settle down.

Not so the "Father of the White Monkey," as he is called by the Karen, an ethnic group of 7.5 million people largely based on a hilly sliver of land bordering Thailand. This former special operations officer, who asked to remain nameless due to the senstivity of his work, is now in his 40s. But, far from taking it easy, he lives and works deep inside Karen state, where there has been an ongoing civil war since 1949, making it one of the world's longest ever.

The Father of the White Monkey, or Tha U Wa A Pa as he is called in Karen, has taken it upon himself to help the Karen in their struggle for statehood. He, along with a team of about 50 trek up and down mine-ridden Karen mountains day in and day out, distributing aid and training a force that has become known as the Free Burma Rangers.

When he left the U.S. Army, Tha U Wa A Pa, went to visit his father, a famous Christian missionary based in Thailand, where he became interested in Burma’s struggle for democracy. At the time, Burmese democracy icon and opposition leader Aung San Suu Kyi had just been released from house arrest, though she was later put back under house arrest and only freed again in November 2010.

“Daw Suu Kyi had just been let out and my sister suggested I go and see her for guidance as to how I can help,” he told Global Post sitting around a makeshift table at his organization’s temporary headquarters nestled among bamboo groves, deep in the Karen jungle.

“I was blown away by her humility, her strength, and her love for her people — she asked me to help her people, unite the ethnics and pray — that’s what I have set out to do.”

Following the secret meeting with Suu Kyi, he traveled to the Thai-Burma border where the regime’s army had launched a widespread offensive against the Karen National Liberation Army (KNLA), which is the largest ethnic rebel force fighting for independence from the rest of Burma.

Karen highlanders have maintained ties to Western Christians — notably American Baptists — since missionaries arrived in the region in the 19th century. Christian foreigners established a network of schools and churches, which eventually helped coalesce various Karen tribes into a united struggle for Karen statehood.

On arrival Tha U Wa A Pa stocked his car up with medical supplies and drove down to the spot where he remembers tens of thousands of refugees fleeing from the intense fighting.

There, he met Eliya Sampson. As Karen refugees literally rushed past over into Thailand, Tha U Wa A Pa says he remembers a soldier jumping out of the bush with a grenade launcher and red earring.

“I was like man, you look like a pirate, and he told me his name was Eliyai and that he was a medic and asked if he could help me,” said Tha U Wa A Pa.

Together they went along the border distributing aid, in what was to be the beginning of the Free Burma Rangers (FBR).

“I had no weapon, little money and no power but I thought if I could help one person then they would be happy, and I would be happy.”

Despite his modest ambitions, Tha-U-Wa-A-Pa and Eliya went on to help thousands of villagers as they trekked for months across the war-torn Karen mountains.

"We would travel with four or five people, fill our backpacks up with medicine. We were like ants,” he said. “When the medicine had run out, we would come back to the border, stock up, and just go again, and again, sending out reports whenever we could.”

From one initial team of “rangers,” FBR has expanded over the last 13 years to 53 and the number continues to grow. Tha-U-Wa-A-Pa is more than eager to point out that over 250 local staff members, who risk their lives on a daily basis to help their people in the war-torn ethnic areas, do the main work.

Tha Da Der village is the first destination after a two-month, multi-ethnic training deep inside Karen State for 10 new teams and seven existing teams. The medics come from every ethnic group in Burma, and are handpicked by their leaders.

“I used to be a soldier but wanted to be able to help my people more directly, Free Burma Rangers gives you the training to do that,” said Saw Tu a Karen medic, as he pulls out a patient’s tooth at the temporary clinic set up on paddy fields next to Tha Da Der.

Last June the regime’s troops advanced on the Tha Da Der village and burned down the church, school and over 35 homes. They also burned their livestock, part of a brutal four-cuts policy, which aims to disconnect the rebels' support base. Luckily, the villagers were warned before and Karen soldiers were able to recapture the village.

“I can still remember the smell of our cattle drifting through the valley and returning to my house smoldering,” said Saw Plo, an elderly man, standing within a burned out wooden frame, which used to be his home.

“It was very difficult for us to rebuild our lives, but with the help of the rangers we could do it.”

Next to the clinic, the rangers have organized “the good life club” for children. Designed by Tha U Wa A Pa’s wife – who is also American and lives in the jungle with him and their three young children – the program is designed to educate and support the children in the conflict area.

As well as the community program and providing aid, the rangers are also dedicated to documenting all human rights abuses they witness. Along with volunteer security units, every team has a documentation officer who records all the events, often taking great risks to film the widespread abuse committed against civilians.

FBR has a strong Christian foundation. Tha U Wa A Pa belives himself to be an ambassador for Jesus, but the FBR also help and welcome people from all religions, he said.

The Free Burma Rangers have been a great help, according to Gen. Baw Kyaw from the Karen National Liberation Army.

“FBR has brought technology to the Karen people and enabled us to tell the world what is going on,” the stocky general told GlobalPost from his secret jungle hideout where he controls most of the army’s northern command.

“If they hadn’t come, we would have faced many more human rights abuses,” he said.

Tha-U-Wa-A-Pa remains humble about FBR's operations.

“We’re just tiny,” he said. “We’re really more of a disorganization. We’re just an organization out of necessity but I hope we are lighting small fires of hope and love across Burma.”

Despite his humility, FBR supplied medicine to over 100,000 patients last year. Moreover, the rangers are laying the foundations for inter-ethnic cooperation, which many hope will benefit Burma’s ethnic areas for years to come.

As the medics packed up their equipment and set out to their native war zones this past January, the camp buzzed with excitement.

“We are a small group going up against a mighty evil force, but we have the love and dedication to struggle on,” said Sunshine, a young Karenni "ranger," before disappearing into the jungle.