Why wars are bad and their disadvantages?
Your question assumes that all wars are all bad. Obvious answers are death and destruction, effects on the economy, taxes, strain on the infastructure and possibly the environment. The hidden answer is the effect on the war fighters themselves, their families and their sacrafices, effects, both positive and negative, on bussiness, schools, etc. Of course, your perspective will be much different from a safe environment as opposed to the answer you’d give if there were tanks on your street and you were in danger every waking moment. Be thankful for those who have made it possible that you can live in peace and ask such a loaded question.