Clinton did what a lot of people did...avoided service in an unpopular war that was likely illegal and was certainly immoral. George Bush was in the National Guard for exactly the same reason, to avoid going to Vietnam. He couldn't even manage that little bit of work though...he forgot to show up.
Clinton isn't running this time though. I know a lot of Republicans are having a problem with that, but it's true. Clinton served his two terms as president and now, like it or not, has retired from the life of a professional politician.
John Kerry is running. He's a decorated war hero who served in Vietnam then, when he got home, publicly and vocally opposed the war because he had seen what a mess it first hand. His parents were wealthy enough to send him to school in England. They were well-connected enough that they likely could have scored him a gig alongside George in the National Guard. Hell, he could have come to Canada. He didn't do any of those things though.
If you want to play duelling military credentials, then you have to play against that record.