Anyone still out there after that verbal buffeting from Nigel Dodds ? Mrrzy - I don't think 'Amhráin na bhFiann'
is the one you're thinking of. The line you cite is a standard expression of the con-job perpetrated by the
British Army with the help of the Irish Parliamentary party (Home Rulers) on the eve of WWI
It sounds similar to the lines from 'The Foggy Dew': 'It was Britain bade our Wild Geese go, That small nations might be free'
Southern Irishmen were also duped into the trenches with the slogan: 'Fight to free poor Catholic Belgium'
'The Foggy Dew' bears no relation to 'Amhráin na bhFiann' - translated as 'A Soldier's Song' - apart from the respective death tolls,
and the proliferation of firearms in each song.

As an aside, there's a peculiar detail from the Norn Iron soccer team's terrible performance in Liechtenstein last night:
"But after two bursts of God Save The Queen - the Liechtenstein national anthem has the same tune as Northern Ireland's - the home side set about McIlroy's team."
So said the Guardian report on the match. 0-0 it ended - at least they didn't do it in a competitive match like us !!
Finally, if by a 'national' anthem you want something to clear the hall at the end of the night, I think both sides of the
sectarian divide could agree on 'The Parting Glass', no?? No use for whipping up sports crowds into a frenzy, though.. :->