All this is, or may be, true. Sure enough, these should be taken into consideration. But it is truer that bringing about an intervention with no good evidence about its potential impact is all too frequent. Money, good will and effort are wasted so frequently when doing development work. In post conflict settings (actually, in all settings) no intervention should be implemented without a reasonable good impact evaluation, save for those instances for which hard evidence has already being accumulated. Given that cases in which no good evidence is available far exceeds cases where that evidence exist, impact evaluation should a feature of all development work , instead of an afterthougt. In other words, we should discuss whether NOT to conduct impact evaluation instead of it should be conducted.