His presidency has been marred, however, by invading and occupying the Democratic Republic of the Congo during the Second Congo War, resulting in an estimated 5.4 million deaths since 1998, and by participating in other conflicts in the Great Lakes region of Africa. He has struggled for years in the civil war against the Lord's Resistance Army, which has been guilty of numerous crimes against humanity, including child slavery, the Atiak massacre, and other mass murders. Conflict in northern Uganda has killed thousands and displaced millions.