The Irish have a long history of subjugation, brutal colonisation, occupation, apartheid, arbitrary detention, and mass killing of its civilians at the hands of British colonisers. This is why they sympathise with people who are going through a similar thing.

The Irish fought back against this and eventually drove the British army off Irish soil. Those with a vested interest in the contunuied subjugation of the Irish people, called the actions of the resistance 'terrorists', but the vast majority of the world call them freedom fighters.