Yeah, literally, it surely refers to war. But luckily good lyrics have a universal underlying theme as well. Whenever I hear this song I think it has the idea of someone who travelled too far down the wrong path. We all have actively engaged in a choice that proved to be the wrong one. Most of the time it's only results in a minor consequence, like stealing a chocolate bar or lying to a friend. Every once in a while it has a serious consequence. In wars you are scarred from seeing horrible impact it has on both your friends and people you hardly know. While some of it was out of your control there is that bit you can be pinned for responsibility. It doesn't even need an external consequence. We are our own harshest critic so most of the damage is internal and self inflicted. Those are the worst because you are your own enemy and no one can save you from that.
My favourite line is "did you try to live on your own/ When you burned down the house and the home"
Literally, it's tough to live without a roof over your head. Like if a bomb hit it; again war. Internally, the loss of a sanctuary can leave you feeling exposed in other ways: like when your parents get divorced or isolation from friends due to alcoholism. It's tough to regain that confidence to live knowing that you made a brutal mistake.
Maybe referencing suicide is an easy way out on this song, but "being in ruins" is a good way to describe it and it is a consequence returning from war.