Mr. Chair, clearly, if a member of the Canadian Forces were to engage in hostilities against the Canadian Forces, that would be an act of treason. They could potentially be charged with the offence of treason, or mutiny, or a variety of other offences, and they would be dealt with under the military justice system.
In respect of other people who weren't members, if they were a spy, Parliament has created an offence of being a spy, under section 78 of the National Defence Act. We would have jurisdiction under paragraph 60(1)(h) to try that person.
Otherwise, it would depend on whether or not the person was a lawful combatant. If they were not a lawful combatant, they might be detained pending the conclusion of hostilities. If they were a lawful combatant, they would be taken as a prisoner of war.