Jemmy O'Brien destroyed patriots. "With his dagger ... would he slaughter The husband, the wife, and the daughter." "The braggart he is now pulled down And all the great lawyers of the Crown Could not save poor Jemmy O'Brien!"
Given its date, this sounds rather like a warning to those who opposed Irish independence. For the background, see the notes to "Jemmy O'Brien's Minuet" and "The Major." - RBW