One that noone has mentioned so far is this one, by Mark Knopfler - and here is a link to a site with a Real Audio of the song.

BROTHERS IN ARMS
Written by Mark Knopfler
As recorded by Dire Straits on "Brothers in Arms" (1985)

These mist covered mountains – Are a home now for me,
But my home is the lowlands – And always will be.
Some day you'll return to – Your valleys and your farms,
And you'll no longer burn to be brothers in arms.

Through these fields of destruction, – Baptisms of fire,
I've witnessed your suffering – As the battle raged higher,
And though they did hurt me so bad – In the fear and alarm,
You did not desert me, my brothers in arms.

There's so many different worlds,
So many different suns,
And we have just one world,
But we live in different ones.

Now the sun's gone to hell, – The moon riding high.
Let me bid you farewell. – Every man has to die.
But it's written in the starlight – And every line in your palm:
We're fools to make war on our brothers in arms.

No specific mention of Vietnam, and in fact it isn't about that any more than so many other wars. But I love its ambiguity - you can read it several ways. I read it as a tribute to the soldiers of the other side in some messy Vietnam type war - the idea being that, in a sense, the people you are fighting can be far closer to you than the people back home, because of shared experience.

But even if that is the meaning, it's not the end of the story - because it's left totally open to the listener to decide which side they imagine "the singer" as fighting on. And that is perhaps the real point.