I've seen threads here on FR with stories indicating that he was anti-war before he even went over there. I'll see if I can find a link.
Yeah, I think I've heard that too.
I found a story last week that Kerry's first cousin was a major of a small town in France who later ran for president of the country. Earlier, he was a socialist, student activist and Greenpeace activist. When they were both students, Kerry visited him and was impressed at the power he generated through students--the people. It may have been his primary introduction to the power generation of socialism.