This book draws inspiration from existing practices of the ICC and analyzes some of these achievements and challenges concerning the prosecution of war crimes/enforcement of IHL before the ICC. The common denominator of all contributions is therefore twofold: (i) war crimes, and (ii) the ICC. All contributions identify and unfold issues that present obstacles on the way to the desired aforementioned goal of a successful prosecution of war crimes. Upon assessment of particular issues, the book reveals whether the stance adopted by the ICC either makes reaching this goal easier (achievement), more difficult (challenge), or potentially both.