How do you explain war to a 6 yr old??

So yesterday was Rememberance Day for us in the Great North. It's a day of reflection and to comemorate those that have past fighting for our country. It's mostly made to remember the soldiers of WWI & WWII. But now alot of our soldiers have gone to Afghanistan too, so it's also to remember the 96 soldiers we've lost in the last 6 years.
So there was alot of coverage of the ceremonies going on and Baby was asking soooo many questions about it. She also had an assembly at school. They were accepting donations for poppies, but I didn't know, and she let me know that I should've sent her with money so she could get one.
But anyways, straying again.
Babe: What's rememberance day?
Me: A day to remember all the people that fought for us
Babe: I don't remember anyone that fought for us
Me: It was a long time ago, before you were born.
Babe: Oh
*thinks for a while*
Why did they fight?
Me: Good question. I don't know
Babe: No really, why were they fighting??
Me: Because there were bad people who believed in bad things
Babe: Oh *thinks again* like the devil
(This was a conversation we had a while ago about religion)
Me: Not really. They believed what they were doing was correct, but they weren't....and it's complicated.
Babe: Explain it to me, i'll understand i promise.
Me: They fight so that we can live like this, where we eat what we want, and watch what we want and no one can tell us what to do. So we live in a 'free' world.
Babe: Oh. So why do there heart breaks?
Me: What??
Babe: Why do they use guns to make people's hearts break.
*how do i explain this*
Me: Call auntie Mary. She'll explain.

My sister is the bomb at explaing this kind of stuff. She couldn't do it either.

The most touching part of this whole conversation ( and there were alot) was that my dad was listening to the whole thing and putting in his cents every now and then. Then baby turns to him and says "You better not go fight in nay war, because I would be so sad if your heart breaks!!"
I think that brought tears to my dads eyes. It did to mine.