The agreement obliges the two governments to continue their cooperation through CTA, coordinate their lists of visa-free countries, develop “electronic border management systems”, exchange data to combat CTA `abuses` and work towards a “fully common short-stay visa”.    The Anglo-Irish Treaty of 1921 (Irish: To Conradh Angla-Éireannach), known to all as The Treaty and officially the Articles of Agreement for a Treaty Between Great Britain and Ireland, was an agreement between the government of the United Kingdom of Great Britain and Ireland and representatives of the Irish Republic that ended the Irish War of Independence.  It provided for the creation of the Irish Free State within one year as an autonomous domination within the “Community of Nations, known as the British Empire”, a status “equivalent to that of the Dominion of Canada”. It also offered Northern Ireland, created by the Government of Ireland Act 1920, an option to leave the Irish Free State, which it exercised. The Ireland/Northern Ireland Protocol provides for the obligation to maintain the Common Travel Area (CTA), which has been in force for most of the period since the creation of the Irish Free State in 1922. CTA allows British and Irish citizens to move freely between the UK, Ireland, the Channel Islands and the Isle of Man and to access different public services in each country. As regards the legal basis for identity and immigration checks at airports and seaports, as carried out for passengers between Northern Ireland and Great Britain, immigration officers may arrest without an arrest warrant any person for whom they have reasonable grounds to commit an immigration offence and/or to be held responsible for removal instructions. Section 31.19.3 of the Enforcement Instructions and Guidance  concerning baljinder Singh v. Hammond stated: “Any consultation must be consensual. The probation referred to in paragraph 2 shall not entail the power to compel any person to take that examination or to require any person to comply with that examination.
If a person tries to exercise their right, not answer questions and leave, there is no power to arrest that person solely for committing an immigration offence. The common travel area does not concern goods or customs. Trade in goods, the absence of customs offices at the border between Ireland and Northern Ireland and the absence of customs duties between the United Kingdom and Ireland will continue during the transitional period (period from 1 February 2020 to 31 December 2020). In addition, future trade and customs agreements between the EU (including Ireland) and the UK will depend on the outcome of the UK-EU negotiations that take place this year. The Common Travel Area (CTA) is an agreement between the United Kingdom (UK) and Ireland, which offers citizens of these countries a large number of rights. It involves more than the fundamental right to travel freely between the two countries. CTA has led Ireland to commit to changing British immigration policy.  This is notable in 1962, when Irish law was amended in response to the Commonwealth Immigrants Act of 1962, which imposed immigration controls between the United Kingdom and Commonwealth countries, while in Ireland, aliens replaced in 1962 the previous state provision that exempted all British subjects from immigration control. only those who were released, born in the UK….