I'll bet there are lots of people active in Australia's peace movement who would love to talk to (or e-mail) your class -- and show that there are lots of non-douchebags! One of my friends who is working outside of Sydney said that many of her co-workers have been lamenting how things are going, and are very upset with Howard ... they have been telling her that Canada "did the right thing" in not following Bush, and wish that Australia had done the same.
Your students might be interested in the book "The Fatal Shore", by Robert Hughes, about Australian history ... it's well-written and I bet even in Grade 7 they would get something out of it, if you gave them an excerpt to read and had a class discussion. I found the section on World War One rather moving (some eerie parallels with Iraq?). Australia lost so many people, and those who got them into the war were just taking them for granted. The anti-war song "And the Band Played Waltzing Matilda" reflects on that (and Australia's Vietnam involvement). I remember one of my teachers played a recording of it for us, when I was in high school.
http://en.wikipedia.org/wiki/And_The_Band_Played_Waltzing_MatildaI guess I'm not the only one who thought it was a great song:
"American Vietnam veteran and Medal of Honor winner Senator Bob Kerrey sang the song to his supporters at the end of his Presidential campaign in 1992, and borrowed the first line for the title of his autobiography, When I Was A Young Man: A Memoir."
Links to some Australian peace groups
http://www.mapw.org.au/http://www.nswpeace.org/http://www.peacetasmania.org/