Iraqi pro-PMU protesters storm US embassy in Baghdad

[Saddam Hussein]

Main reason was Saddam thinks Kuwait use to be part of Iraq and should be his. Not to mention the amount of oil it has so another benefit. Think he also wanted to get rid of some of his debt by eliminating the country that he owed to at the time.

The dispute about Kuwait goes back to before Saddam, Abdul Karim Qasim disputed it and tensions rose to the level that certain troops of military were deployed in Kuwait to act as a deterrence.

Personally I think Kuwait-Iraq can (with proper leadership) focus on cooperation and development instead, if leaving the factor of wealth out of it, it doesn't matter much whether they keep it or Iraq controls it as the identity of the land would remain Arab. We don't need these irredentist movements they cause trouble, the only issues with lands are with the Kurds in the north whom are to driven by nationalism and seek to take all they can.