Keeping the land border between the Republic of Ireland and Northern Ireland free of any visible checkpoints is a key plank of the Brexit accord between the European Union and U.K. An agreement, known as the Northern Ireland Protocol, aims to do just that. Yet, it’s drawing bitter criticism from unionists who claim it undermines their British identity because it treats Northern Ireland differently from the rest of the U.K. The arrangement is also under attack from companies who say it disrupts trade. Following Brexit, the 310-mile (499-kilometer) frontier running from near Derry in the north to Dundalk on the east coast of Ireland became the EU’s new land border with the U.K. Without special status, checks would have had to take place on the frontier because the U.K. has exited the customs union and single market. The concern was that delays could hamper the free movement of people and goods between the two parts of Ireland, which was partitioned a century ago, and customs posts could become targets for violence. The protocol was seen as an answer. By keeping the land border free of potentially provocative checkpoints, both sides hope to prevent a return to the era of sectarian violence, which cost more than 3,000 lives between the late 1960s and the signature of a peace accord, the Good Friday Agreement, in 1998. Subscribe to our YouTube channel: https://bit.ly/2TwO8Gm Bloomberg Quicktake brings you live global news and original shows spanning business, technology, politics and culture. Make sense of the stories changing your business and your world. To watch complete coverage on Bloomberg Quicktake 24/7, visit http://www.bloomberg.com/qt/live, or watch on Apple TV, Roku, Samsung Smart TV, Fire TV and Android TV on the Bloomberg app. Have a story to tell? Fill out this survey for a chance to have it featured on Bloomberg Quicktake: https://cor.us/surveys/27AF30 Connect with us on… YouTube: https://www.youtube.com/user/Bloomberg Breaking News on YouTube: https://www.youtube.com/c/BloombergQuickTakeNews Twitter: https://twitter.com/quicktake Facebook: https://www.facebook.com/quicktake Instagram: https://www.instagram.com/quicktake