Yakobus Mebri stepped in front of his classmates at a training centre in Indonesia's West Java province and, at the top of his voice, demanded if their hearts burned to defend the nation.
"It does! It does! It does!" the recruits thundered back, breaking into what appeared like a war dance.
Their instructor, Major General Hartind Asrin, then asked them to sit down: the Bela Negara - "defend the nation" - class was starting.
"We have to be more vigilant of potential threats in their infancy," he said as students diligently took notes.