Ummm....
Sadam had some legitimate reasons to invade Kuwait. Not enough to justify the invasion of a sovereign nation, but some.
1) There was a legitimate dispute involving oil fields, which he didn't have with any other neighbour, AFAIK. That should certainly have been resolved short of war, but it was a real dispute.
2) Iraq viewed Kuwait like the PRC views ROC - as a break away province. In Sadam's mind, invading Kuwait WASN'T invading a sovereign nation. Of course, he knew the rest of the world didn't believe that, but he thought he could get away with it.
Neither of those reasons apply to any of his other neighbours.
Now... If he HAD been successful with Kuwait, he might later have tried for some of the nearby Saudi fields....
Sadam wasn't a random mad aggressor. Aggressor, certainly. Mad? maybe. Random? no.