Well those who lose their lives suffer the most, when you think about it... I mean they literally cease to exist in any form, as far as they're concerned.
However it'd be silly to say only the soldiers suffer, the family of a dead soldier suffers too, largely due to financial reasons, I imagine.
To be frank, I don't really understand why people actually want to go to war, I don't understand patriotism... okay, well I understand how it's formed(hooray for indoctrination from a young age, I guess?), but I fail to see the benefit of it to the person him- or herself. I mean I'd never go to war for my country, or any other country for that matter... nor for anything else, really.
War is something that makes me feel ashamed of the human race, or rather violence and rampant stupidity and irrationality in general. Ah well, too bad we don't live in an utopia.