Insanity Street by Lillie Palmer is very good:

"And we talk of the coming of peace,
Of a time when hostilities cease,
But we make and we store all the weapons of war
'Cause we live on Insanity Street."

And also Suzanne Vega's "The Queen and the Soldier"

And, for traditional songs, "The Weary Cutters."

And there's a brilliant song called "The King's Shilling" that Jean Redpath sings

And for smaller-scale war, "There Were Roses."