When the Japanese invaded Burma , he was given the task of raising irregular guerrilla forces from the Karens and other groups .
He was later seconded to the 20th Burma Rifles with the temporary rank of Major , becoming an expert in several Burmese languages .
When the Japanese invaded Burmese , he was given the task of raising irregular guerrilla forces from the Karens and other groups .
He was later seconded to the 20th Burma Rifles with the temporary rank of Major , becoming an expert in several Burmese languages .