There hasn't been a "good one" since WW2.

Short explanation: The arms Iraqi forces fought with during the Gulf War were largely bought or built by Americans. Isn't that interesting?

Long explanation: It's all connected to the Israel-Palestine issues we are seeing this very day. Iraq was dealt a very nasty hand by the UN after the dissolution of the Ottoman empire, becoming a landlocked country, with lines drawn such that they were made caretakers of ethnic enemies and forced to forsake much of their geopolitical power and resources to tribal rivals. It's difficult to say their claim to Kuwait was justified, but it's certainly just as difficult to say it was unjustified.
On top of that, we had just gotten done with fucking over Iraq due to their failure in the Iraq-Iran war. They had initially allied with the USSR to prop themselves up, and when that went to shit they turned around and tried doing the west and themselves a favor by grabbing a piece of Iran. We were directly supporting them (anybody taking a punch at Iran is a friend of ours!), and had been increasing our support, but when they agreed to a ceasefire we stopped, leaving them war-torn, deeply in debt, and with really nothing to show for their experiment of working with the west aside from all these shiny American weapons of course.

Medium explanation?: Iraq had been engineered to be an Israel-like anti-Arab agent in the region, but when they failed and sued for peace, we left them no other option but to wage another war to survive. When they went in a direction we didn't like, we got all our buddies together (including a surprising number of old enemies) and decimated them. Twice!