(An ultra-Orthodox Jewish man (R) shows his identification card to a soldier at the entrance to a recruiting office in Jerusalem February 22, 2012. REUTERS/Baz Ratner )

Better trained in wrestling with complex religious texts than in martial arts, the ultra-Orthodox Jewish youths drop to the floor to give their combat instructor a dozen push-ups.

Black skullcaps slip off their heads and a pair of glasses goes flying across the room as the khaki-clad trainer barks out: “I will kick your ass if you do not keep time.”

The 15 young men have chosen to go against the norm of their reclusive community. They are training for military service, a two-to-three-year obligation that binds most Israelis, but from which the ultra-Orthodox, or Haredim, are mostly exempt.

Not 10 minutes drive away, posters in Jerusalem’s ultra-Orthodox neighborhoods scorn Haredi men who choose to serve in the army and quote rabbis who rule against the practice they fear will lead their youth away from piety and into bad ways.