from thread a couple pages back-I replying midway down the thread starting here: http://www.habitablezone.com/currentevents/messages/43253.html
Bringing this thread forward:
I said
...."So there will be no shortage of "UN and NATO assistance and support"- "too much" might a problem:)"
Which Davin put this way:
' "So there will be no shortage of "UN and NATO assistance and support"

Well, we'll find out soon. Shall we define the terms and conditions for a wager?'

I'll start by defining my point. Which is that there will be international support. By which the US govt could be characterized as coordinating international groups (groups including governmental and nongovernmental parties). One of these groups will be the UN (which also coordinates governmental and nongovernmental parties). The US miltary will liason with state dept and other groups: UN, other govts and their miltary. This is the typical way the US operates.
Obviously Iraq isn't a NATO member, but Turkey is a NATO member so there no doubt there will be NATO involvement at least in the form of Liason between other NATO members and Turkey. NATO has various assets not merely hardware, but intelligence and expertise in warefare related areas. And obviously two major NATO members are involved (America & UK).
Though all the above isn't really what we are talking about. The question I guess is how much involvement will nations other than the US and UK have at the time of invasion, regime change, and follow through of rebuilding the state. I don't think the true involvement of other countries can be easily quanitified. For instance what extent was India involved in the recent regime change in Afghanistan. I don't know but it certainly wouldn't be surprise me if there was some "significant" involvement. Or what was Iran's involvement. Generally speaking the more "quiet a country is" and coupled with it being in the region, the more reason there is to suspect some involvement. Another way of looking at this is that countries in the region have the strongest interest in countries on their borders, their govt officals if they have dipomatic relations with US or UK will want to influence the US and UK and working together is in the interests of all parties involved.
Since it is in the US's interest not inflame any Arab prejudices, one thing the US is going to "get" from the "interested parties" which "represent Muslim interest" is there involvement on the ground in Iraq. These policing powers will need to be well trained & professional- otherwise they could cause more trouble "than they are worth". So the most valued force would be muslims and a good track record in other peace keeping roles.
Therefore in order to predict which countries will be involved you could probably examine other recent UN actions.