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“Don’t go Jack” -- it's a phrase that every defence force member knows well but is lost on the rest of us.

It means never dob in your mates, don’t admit who might have been responsible for bad actions, and always have each other’s backs. This mantra is excellent to build small group cohesion, esprit de corps and fighting capability.

However, it also begins the process of subverting command, encouraging bad behaviour and compelling fellow members to cover up incidents and protect wrongdoers.