Ochi reason number one...

[kandrathe]

Most of the Iraqi deaths under Saddam occured due to the war with Iran.

Casualty figures are highly uncertain, though estimates suggest more than one and a half million war and war-related casualties -- perhaps as many as a million people died, many more were wounded, and millions were made refugees. Iraq's victory was not without cost. The Iraqis suffered an estimated 375,000 casualties, the equivalent of 5.6 million for a population the size of the United States. Another 60,000 were taken prisoner by the Iranians. Iran's losses may have included more than 1 million people killed or maimed. The war claimed at least 300,000 Iranian lives and injured more than 500,000, out of a total population which by the war's end was nearly 60 million.

Federation of American Scientists - Iran/Iraq War 1980 - 1988

The first Gulf War (according to the Iraqi sources) resulted in 2300 civilian, and ~ 20,000 military casualties. I would argue that as Iraq was the aggressor, who was then repelled from Kuwait, that Saddam actually was responsible for those casualties.

I would offer this evidence that Saddam's brutal security forces have inflicted hundreds of thousands of more civilian casualties than any external military forces. Of considerable brutality were the crushing of the Kurds, and the Shiite uprisings in 1991.
Human Rights Watch International - Iraq