A classic against war and all its nonsense. Soldiers are victims, heroes, fighting other people's battles.

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 battles raged higher
And though they 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
And the moon's riding high
Let me bid you farewell
Every man has to die
But it's written in the starlight
And every line on your palm
We're fools to make war
On our brothers in arms

MIST= Light fog.
"These mist covered mountains" = "These mountains which are covered with mist". The words "mist-covered" are placed before the noun "mountains" and so they work as an adjective, although originally they are one noun and one verb.

THE LOWLANDS= A part of Scotland (as opposed to "the Highlands", with lots of mountains).

BROTHERS IN ARMS= Companions in the battle, my soldier mates, my fellow soldiers (the other soldiers in my army). He says "brothers" and not "fellows", so that means he loves them, he feels they are like family.

BAPTISMS OF FIRE= Baptism is the ceremony through which you become a Christian, but we also use this word for any ceremony or action that makes you become something or get a new experience. So a baptism of fire is your first battle, when you become a real soldier.

WITNESSED= If you witness something you were there when it happened, you saw it and you can give testimony of it.

AS THE BATTLES RAGED HIGHER= When the battle was getting more cruel and terrible.

DESERT= Abandon.

BID YOU FAREWELL= (old fashion, poetical) Say goodbye to you.

STARLIGHT= The light from the stars. "It's written in the stars" means "it's our destiny".

EVERY LINE ON YOUR PALM= The palm of your hand is the inside part of it. Some people say they can read your future in the lines of your palm, so the lines of your palm is where your destiny is written, same as in the stars.

WE'RE FOOLS TO MAKE A WAR ON OUR BROTHERS IN ARMS= In this line, the punch line of the song, we discover that when he was talking about his "brothers in arms", the fellow soldiers he considers like family, he's not talking about his friends as opposed to the other soldiers, the enemy; he's talking about all soldiers, on both sides, because all soldiers are victims in every war. Wars are something stupid that some people promote and then soldiers, from one side and the other, have to go there and hate each other and kill each other just because some people decided that they have to. But he doesn't hate anybody, he just wants to go back home.

He's talking about his brothers in arms, and we think that, obviously, he's talking about his fellow soldiers that are fighting the enemy with him. But suddenly, the last line tells us something completely different:

WE'RE FOOLS TO MAKE A WAR ON OUR BROTHERS IN ARMS

So when he says "brothers in arms" he's not talking about his friend soldiers, he's talking about the enemy, because they are also his brothers in arms. They, like him and his friends, are fighting in a war they didn't decide and are killing and dying because other people decided they should. So he feels they are all in the same situation, victims of other people's interests.

Unfortunatelly, most wars in the past and today are like this, a group of important people decide that they want to make war on another country because that will make them richer and more powerful, and they send their soldiers to hate each other and kill each other, and most of them don't even realize they are just puppies in a stupid war.

(I said "most wars", should I say "all the wars"? I don't know, I suppose if you fight for freedom that would be fine, right?, though many times they make you think you're fighting for freedom when in fact they want you to fight for other reasons, so it's complicated)