True.
Thankfully they were massively outnumbered by those who fought the Wermacht, SS, Luftwaffe and Kreigsmarine....
Even many who hated the British stopped well short of supporting the odious regime of Hitler.
I would recommend to you a memoir by Hugh Leonard, the fine Irish playwright, entitled “Home Before Dark.” He recounts his Dublin childhood during the ‘30s and ‘40s. His wonderfully naive and kindly adopted father (”Da”) was continually giving the Hitler salute during the War - only to be excoriated by his fellow Dubliners. He had fought during the 1916 Revolution and was very bitter towards the English - the awful Black and Tans.
The Irish have a very sad, mixed-up history...