Because it's always the same.
When you fire the first shot, no matter how right you feel, YOU HAVE NO IDEA WHO'S GOING TO DIE! YOU DON'T KNOW WHOSE CHILDREN ARE GOING TO SCREAM AND BURN! HOW MANY HEARTS WILL BE BROKEN! HOW MANY LIVES SHATTERED! HOW MUCH BLOOD WILL SPILL.
Until everybody does what they were always going to have to do from the beginning...
SIT DOWN AND TALK!