I think you are confusing war with disease.
Not really - if you check your history you will find that disease follws war very quickly. The two are inter-realted.
In fact, you could have some real sickly speciments 'winning' just by pushing buttons.
Not really - I am talking about in general. Those that push the buttons tend to be in Command positions - they tend to have a certain type of gene - so in the long run (not human time scales) those genes get passed on and are in general "beneficial" to the human race