Perpetrators of atrocities should be prosecuted, no question. It is no good for foreigners to try to heal their wounds. It won't work. Conservatives in the U.S. oppose the ICC because they fear American troops may be snared by its jurisdiction while on duty abroad. We'd take it one step back.
Laws are binding in each country because of national sovereignty.
Therefore, its decisions aren't strictly enforceable. The ICC will have no police power over nations. But again, for reasons of the precedent this would set, thank goodness. There are other flaws. For while the ICC has no universal sovereignty, signatories are asked to cede to it a degree of their political independence.