But the Karen now find themselves playing a leading role in a drama no longer confined to the misty hills along the Thai-Burmese border, thanks to a brutal Burmese military regime in Rangoon intent on crushing the nation's nascent democracy movement.
For the first time in their history, the Karen have united with 19 other opposition groups, including fellow ethnic insurgents and dissident students, making Manerplaw the opposition headquarters of Burma.
And with the nation a tinderbox - six months after Burma's military dictators voided an election they badly lost - the opposition on the border could be the force that strikes the match.
For that reason alone, Manerplaw is now considered the Burmese army's prime target in a dry-season offensive expected to begin next month.
Early each morning at Manerplaw, the young recruits file by in formation out on the exercise field, training to take their place on the front lines.
Maj. Yaw Mu watches them pass. He is 50 and has been fighting the Burmese regime for exactly half his life.
He points off into the jungle, over the mountains to the west that shield Manerplaw, which means "victory field" in the Karen language.
"If you go here, 1 1/2 days' walk, you reach the front line," this hard warrior with a flattop haircut says. Then he points north and south and says the same thing.
"Everywhere," the major adds, "is the front line."
At the entrance to the exercise field stands a gate, emblazoned with the motto of the 10,000-man Karen National Liberation Army, "Give me liberty or death."
*
Burma's jagged border with India, China and Thailand has long been an untamed frontier, contested by ethnic insurgents, opium warlords, even remnants of Chiang Kai-shek's Kuomintang.
