Here's a lovely traditional Irish anti-war song that I learned from the singing of Frank Harte. You can hear Mr. Harte singing it himself here:
https://www.youtube.com/watch?v=jK9sXomuBGo

THE NIGHTINGALE

Oh, woeful was the day when I was pressed to sail afar
And leave behind the girl I loved in the town of Balnagar
The shady groves were my delight till I was forced to sail
You all may guess at my distress, lying in the Nightingale

Oh, grief and woe that I must go and fight for England's king
I do not know his friends or foes, and war's a cruel thing
The Nightingale lies near at hand, my time, alas, is brief
From purling streams and mountain rills I part with bitter grief

No more I'll walk the golden hills with Nancy by my side
Or stroll along the sun-bright rills and view my land with pride
We sail away at dawn of day, our sails are ready set
When old Ireland's shore I see no more I will sigh with deep regret

But all has changed and I must range across the ocean wide
Our ship she may, in Biscay Bay be sunk beneath the tide
If I should fall by cannonball or sink beneath the sea
Good people all, a tear let fall and mourn for mine and me

But if God should spare my greying hair and bring me back again
I will love far more my Antrim shore, its dark blue hills and glens
Around my fire but one desire, God grant till life shall fail
To keep my far from cruel wars and from the Nightingale