"Operation Desert Crossing"
GWU's invaluable National Security Archive rounds up documents related to the 1999 "Operation Desert Crossing" war game here. Casual fans will probably want to read this after action report briefing the full report fleshes out some details, but doesn't seem to me to introduce a ton of extra material and the miscellaneous emails are fun.
Scanning some of the reportage on these documents, one thing that I think often isn't being made clear is that the "Desert Crossing" scenarios were assuming the presence of some kind of crisis to prompt US military intervention -- either the collapse of Saddam's regime due to internal factors, an imminent Iraqi threat to a regional ally, or something else along those lines. This isn't a "how to" guide for an unprovoked American invasion, it's an effort to find the best possible way to cope with a difficult situation. Note that it's not very optimistic that the more far-reaching American goals are achievable. They say an Arab coalition will be necessary to have legitimacy in the area, but that such a coalition will make it hard and/or impossible to sustain a long-term American military presence or the establishment of a democracy. They also say it'll be vital to secure Iranian cooperation, perhaps through lifting sanctions, and certainly not that a post-Saddam Iraq could be used as a base for launching anti-Iranian initiatives.