[This site claims][1] that, in modern warfare, about 3 civilians are killed for every combatant killed. 

> This concept can be scientifically proven by understand (sic) the basic concept of “civilian casualty ratio”, that is in every conflict you need to look at the number of civilian causalities versus the number of combatant causalities. This ratio obviously differs from conflict to conflict, but the average in modern day warfare is between 3-4:1. Estimated ratios in NATO operations in Afghanistan were 3:1, western campaigns in Iraq and Kosovo were believed to be 4:1, and the conflicts in Chechnya and Serbia were much higher than 4:1. That is to say that for each combatant that is killed 3-4 or more civilians are killed.

They then compare this statistic favorably to [Operation Cast Lead](http://en.wikipedia.org/wiki/Gaza_War) and [Operation Pillar of Defense](http://en.wikipedia.org/wiki/Operation_Pillar_of_Defense), in which the civilian casualty ratio was about 1:1 (i.e. much more focussed on avoiding civilian deaths). 

I had a bit of trouble finding the specific UN statement to which they referred. 

Can anybody here please determine whether that statement is accurate?

  [1]: http://jewishpreppers.com/2012/12/are-causalities-of-war-acceptable-to-israel/