Three-Part Riddle

Okay, here's my first riddle for everyone. Three parts, three answers, one subject.

The General's Report:
I am a man, committed and bright,
My heart is golden, my burden is light.
What I intend, you don't need to see,
But what I discard, you verily might.

A Mother's Caring Letter:
Near every night I watch over you;
I'm always old, I'm often new.
Some still don't believe, some said not to try,
But together we saw half the world, you and I.

A Soldier's Cry:
I often come, I often go, but never really stay.
I'm only seen among my foe... or always, anyway;
For when in pleasant company, the splendor hides my face.
I'm stranded in an empty sea, which is a lonely place.