Is making peace hard? It has been 25 years since the end of fighting in Northern Ireland. But did the island ever really achieve peace?
Ireland torn by drugs, debt and kneecappings
Watching: Murals have become symbols of Northern Ireland, marking out republican and loyalist areas. Glossary
USA - The United States of America is a country in North America. It has a population of 329 million.
Joe Biden - An American politician who was the 46th president of the United States from 2021 to 2025.
Belfast - The capital of Northern Ireland.
Good Friday Agreement - The treaty that ended the Troubles, a decades-long conflict between Catholics and Protestants in Northern Ireland, which also saw fighting between the British government and Irish republicans. One of its central tenets is an open border between Northern Ireland and the Republic of Ireland.
Northern Ireland - A small part of the island of Ireland that is one of the four nations of the UK. Northern Ireland has had a troubled history because of divisions between Protestants, who mostly identify with the UK, and Catholics, who would like to be part of the Republic of Ireland.
Republicans - People who believe a country should not have a king or queen, or in the US, members of the Republican party.
Republic of Ireland - A European country that is made up of most of the island of Ireland.
United Kingdom - A country in Europe made up of the whole of the island of Great Britain (England, Wales and Scotland) and Northern Ireland, the northern part of the island of Ireland.
Organised crime - Planned criminal behaviour, often involving lots of people working together over a long time to make money. Organised crime often centres around the sale of illegal drugs.