If a Brit joins the French Foreign Legion, or any other foreign army, they would be committing a crime but it's punishable by fines and imprisonment.
Think this only applies if they join the forces of an unfriendly state fighting a friendly state.
I don't think so. There were suggestions that Brits joining the Ukraine armed forces were committing an illegal act (after Liz Truss suggested it was a good idea) but I guess there's a consideration whether it's in the public interest to prosecute
@aggi started
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Think this only applies if they join the forces of an unfriendly state fighting a friendly state.