Yep, absolutely terrifying!

There's always the old chestnut that if your country doesn't develop it, another country (or well-funded faction) with fewer scruples will, and if they think that their tech gives them a significant advantage over you, war is more likely (because they will have a much stronger belief they can win / win at a lower cost).

That's also why we see slick video reveals of stealth bombers and missiles nowadays. The best weapon is one you never have to use in anger.