A traitor is a betrayer - one who practices injury, while professing friendship. Benedict Arnold was a traitor, solely because, while professing friendship for the American cause, he attempted to injure it. An open enemy, however criminal in other respects, is no traitor.
Benedict Arnold was a war hero, wounded in battle--before he turned against his country. Hitler was likewise a decorated and wounded veteran of the First World War. Being a war hero is not a lifetime...exempt[ion]...from responsibility for what you do thereafter.