Why are wars lethal? Why wars are not fought through competion of intelligence of armies or why they are not paintball fights or water wars? Why higher capacity of life taking and performance of damage to life is an indication of being stronger? Under what conditions wars wouldnt be lethal?
You might go to violent war..... you might already have gone to violent war.
Have you ever lost your temper? When a country does this, it's lethal.....
If a robber ran at you in the darkness, would you defend, or would you say, 'Hi! OK..... we can handle this non-violently! I have a dice..... want to play for my watch?'
Cops have to fight lethal battles on your streets every day..... they're just smaller versions of war.
So when a country comes at another, violently, for its land or other wealth, it's violent war.