In order to win the Vietnam War, the U.S. is killing Laotians. Decades after the war ended (NPR).
If you are advocating for a particular war, you are advocating for something that will bring many long-term negative consequences, many which cannot be predicted before the war begins. Proponents of the Iraq War could not know that the specifics of Abu Ghraib would happen; however, they should have known that all wars bring about atrocities, and that something like Abu Ghraib would be likely to happen. Just as dropping bombs from the sky is likely to kill innocent civilians. In that sense, the many questions to ask before considering war should include: "Are the outcomes of this war worth the atrocities that are bound to occur?"
I think advocates of war must be forced to acknowledge the unknown, unpredictable, and largely negative consequences that large-scale violence brings about. If you use violence against a region, there are long-term consequences to the human beings living in that region. Many of these specific consequences may be difficult to predict at the time--but that there will be consequences, largely negative, is quite easy to know from the history of human experience.