Well I finished casually here, looking for the text of a song I had heard and liked... and I'm not Irish and I didn't know was a patriotic song. But what I think is that the text is beautiful and moving. In my interpretation the sense is that for the powerful British to keep their rule on a little poor country as Ireland is really not that important, something you can "laugh" and "joke" about. While for the Irish is a matter of liberty and dignity, at the point that even young girls are ready to die for that. And the soldier understand and so he choose to go away. It means that if powerful nations learn to respect the rights of weak people bloodshed can be spared and I don't see how a song like that could be seen as encouraging terrorism or war.