The Battle Lyrics
I personally think that this song is about a couple who's relationship is deteriorating because the guy is seeing another woman. They're constantly fighting, and eventually split up, but still have regrets or are unsure about the break-up ("Did I lose the battle or win the war? / I move my plans forward but the world was unsure"); even so, they're both jaded now ("As the sun went down and I looked / I knew it would be alright ; But you just sigh, please don't be shy / I'm far too gone to even care who I fight / I feel a little older, when it's over, it's over now.)" The girl doesn't understand why the guy would throw it away for someone else ("I just don't know what you're fighting for") and lost her whole relationship because neither could compromise on the other woman; she can't believe that it could go this far with him continuing to defend his decision ("Now I lost it all 'cause no one surrendered / And all of this and you still defend her").
By the way, when I listen to the song, I hear, "Choose a side, please don't be shy" instead of "But you just sigh". In my opinion, this makes a lot more sense; she wants him to commit to whatever choice he's made.
Lovely song. Their music is so lovely and smooth.