I believe in that a coin always have two sides (or three, or infinite…). For example that everything good can be used for evil.
If you make the best [random killing device] then you are also very knowledgeable about the weaknesses and the best ways to counter it.
Similar to doctors who save lives could be the best at taking lives.
Living in Sweden I know that most of our weapons will probably never kill anyone. Even the countries we sell weapons to will hopefully never use them and that ethical responsibility I thrust the government with. Sweden would not be the highly developed country it is today if it were not for the domestically developed weapons in which we have gained knowledge to apply in other fields and new businesses.