Which bits in particular? And who is eroding it?
If you're talking about Gaelic culture then I'm afraid to be the bearer of bad news, but that particular capall has bolted long ago.
If you're referring to a perceived simple life we led a few decades ago, then that has more to do with new generations of natives rejecting it and opting for a more ambitious/busier lifestyles(for better or for worse) that don't revolve around spending days in smokey pubs, saucing away the day ducking the boss or the dole inspector.
If you feel that our streets are getting darker and you're equating being Irish with being white, then that would be the old ray-cism Ted! I don't remember our culture being under threat of erosion when thousands of lads and lassies came over from the East back in the late 90's and beyond.
Now, for balance, do I feel that there should be an onus on new arrivals(to any host nation)to adapt to the local status quo? Absolutely, hard to enforce it but definitely should encourage. Should any new arrivals seeking/been granted sanctuary here commit crimes? Process over. Rescind any privileges. Deport!