Yes, but the Ireland/ n. Ireland border was never actually agreed on and is still technically in dispute. Which was always going to be the 'excuse' for continuing hostilites, should any excuse for bombing and murder be acceptable!
Which shows the problem with having one part of British government be arbitrator between another part of itself and another country. And the alternative? Withdraw and let the Irish (as a whole, whatever their current nationality, religion and leanings are) fight it out between them?
I am sure that was mooted, way back when... not sure how it owuld have panned out.
Basically, The Troubles are probably an unsolveable puzzle... and I am interested to watch the other 6 episodes to see if I learn more, come to another conclusion.