Doing a wrong thing for the right reasons?

So let's say an army officer is caught by the enemies and wants to spill the beans. The patriot officer can either lie and mislead the enemy and get killed or can betray the country by telling all the secrets of the state. So according to Buddhist principles which is worse? Lies or betrayal? Can you lie for a greater cause? If one's intentions are for the greater good can it still be bad karma?