It's weird to hear stories straight from people who were there for the actual wars on Earth. It's relatively peaceful planetside now as far as international conflict goes, but that definitely doesn't mean that space is easy to deal with.
We've lost far more people than I'm comfortable with on our mission. I'm a captain and my job is always to protect my crew at any cost to myself but it hasn't prevented...casualties. It only takes one judgement call to get somebody injured, or worse.
I don't really feel comfortable sharing other people's stories, but I guess my own is good enough. My dad died just seconds after I was born to a Romulan hell-bent on destroying the life of a friend of mine. Every year, they had a memorial service and we all mourned a man I'd never met, never even...seen. It affected my brother and my mother a lot, though.
I also lost a lot of friends when I was on Tarsus IV. I've never told anybody that, actually, just Pike, but it wasn't a war. We were kids in some guy's eugenics experiment that went horrendously wrong because we survived. I'll spare you the gory details of surviving on a colony with no food.