Northern Ireland

Since the attacks last spring in N. Ireland, I feel like they've constantly been in the news. I know the story of conflict and shit in the area, but I really want to know is why?

What does Northern Ireland produce that the U.K. wants so bad? Do they have good resources? Or is it just another area to tax to make money (which I'm sure it is). IMO, Ireland should be one and not split. There is no clear reason why the U.K. so badly wants it...

Amerifag of some Irish origin here

I don't really know why this conflict has gone on as long as it has.  I get the Irish side of things -- Eire is Eire, but why do some N Irish fear joining Ireland?  Why is this split between Cathlics and Protestants so important to people?  (my point of reference in the US is my family which gets along quite well despite being Lutheran on Dad's side and Catholic on Mom's side. In America religion isn't something that divides.)  I guess the English just want the taxes, but even then, I don't think that the cost of security in N Ireland and the taxes collected make it worthwhile for them.