This is an important question from a legal and humanitarian perspective.
In legal terms, targeting civilians is a war crime. Accidentally killing or maiming them in the pursuit of legitimate military objectives is, well, just too bad. So in judging government’s records of compliance with the law, one needs to measure the difference.
There are policy ramifications to such measurements as well. Over time, atrocities against civilians seem to be falling. But at the same time, some governments seem more complacent than ever about accidental deaths. The assumption behind the wiggle room in the law is that if countries do their best not to hit civilians, then collateral damage will always be the least of the problem for civilian populations. And perhaps this was true in earlier times. But what if in fact the majority of civilian deaths worldwide now come from these “accidents of war”? If so, this would suggest that the laws of war are woefully outdated – that even if fully implemented they do not, in fact, do enough to protect civilians. In that case, humanitarian organizations really should be in an uproar.
So what percentage of total civilian deaths are “collateral damage” and is this percentage trending up or down over time? I’ve begun investigating the answer as part of my current book project, and as far as I can tell, no one really knows. Human rights reporting generally doesn’t distinguish intentional from unintentional deaths, treating all civilian casualties as the tragedies that they are. Neither do academic tools such as the Dirty War Index or various datasets on conflict fatalities in general or civilian victimization. Even databases that count casualties for specific wars, like the Iraq Body Count, tend to break down the data into the type incident (suicide bombing v. shooting) rather than the intent of the perpetrator. And if a comprehensive study exists tracking unintentional civilian deaths worldwide, I haven’t heard of it.
So if any of you has, please let me know.