I don't quite follow what you're saying here because the iron-handed Saddam Hussein had very little violence in his country except for what he himself perpetrated with his sons. After the Iran-Iraq war was over, Iraq was relatively peaceful for many years.
Everybody knows why Saddam attacked Kuwait; it was "slant-drilling" under Iraq's territory. Not only that, Kuwait was once a part of Iraq, so Hussein already did not like the split which was engendered by Britain and the USA. I don't blame blame him one bit.
Iran is Shiite, Iraq was Sunni, what did you expect?? The two religious factions will never get along. We gave Hussein many CBR weapons because of Iran's taking of our Embassy, and we hoped he would prevail. Hell I was too, I hated the Iranians for what they did. Unfortunately our support wasn't enough.