<|begin_of_text|><|begin_of_text|><|begin_of_text|>There is no easy option for Northern Ireland after Brexit.
Deciding on post-Brexit border arrangements between Northern Ireland and the Irish Republic is becoming an issue for which the phrase "the devil is in the detail" could have been coined.<wm> Unlike many arguments in previous negotiations between Ireland's and UK's leaders that were largely focused on what they could gain. Instead, the EU leaders will have to reconcile the existing arrangements. This can be done by using EU principles, such as the Common Rule Book (CRB) or EU-wide rules that are binding on both parties for trade and immigration.
Brexit means that Northern Ireland is likely to leave the EU’s Single Customs Area for some time. This is a formal relationship between Northern Ireland and Great</wm> Britain and has most likely remained since 1921 following a form of ‘common citizenship in the form