I expect Japan or S.Korea to supply the bulk of the troops. We'll probably provide naval and air force backup. Why? I think we're headed for war with Iran and our troops in Iraq are crucial. See the link for where military exercises will be conducted.
http://www.freerepublic.com/focus/f-news/1717718/posts
I agree we're headed for war with Iran - so who do you think will join with them other than North Korea?