Second, after losing her majority in the 2017 election, May was forced to enter into a so-called « confidence and supply agreement » with the 10 Members of the Democratic Unionist Party to govern. The DUP sees a united Ireland as an existential threat to its British Protestant identity. It is the largest party in Northern Ireland since the Good Friday agreement, although it represents only about 36% of the electorate. As far as Brexit is concerned, a « hard border » means a limited number of authorized (and physically controlled) crossing points, occupied by customs officers and police and supported by military personnel in times of tension.  Drivers of vehicles crossing the vehicle must report goods during transport, commercial carriers must submit bill of lading and prove that the goods meet the minimum standards of the area concerned. Tariffs (in the form of tariffs) may be due.  This was the position at the border between 1923 and the Single European Act of 1993.  (In this context, a « hard border » does not mean a fortified border, but during the unrest British security forces blocked many unauthorized crossing points for security reasons. In accordance with the provisions of the Common Travel Area, British and Irish citizens are free to cross the border without passport control. US Senator George Mitchell, who led the belfast agreement negotiations, said he believed the creation of a border control system between the Republic of Ireland and Northern Ireland could jeopardise the deal.  Surveys published on 18 February 2019 by Irish Senator Mark Daly and two UNESCO Presidents indicated that the reintroduction of a hard border would lead to the return of violence.     14 Therefore, the GFA, as a common and reciprocal redefinition of British and Irish national sovereignty, constituted a remarkably incomplete and unfinished constitutional process in Northern Ireland. The withdrawal of the United Kingdom and its border problem in Ireland show that the 1998 agreement did not go far enough to provide for an explicit, indisputable and constitutional (new) definition of the Dublin and London obligations as the sovereign guarantee of the agreement.
6 This very brief historical sketch of the evolution of cross-border social and commercial flows since 1973 shows that the socio-economic normalization of the Irish border is not only the result of European decisions and influences. Above all, it is a direct result of the evolution of relations between London and Dublin on the issue of Northern Ireland in the wider context of Europe. The Irish border, which has been an intra-European border since 1973, facilitated a finely balanced political compromise on the whole of Ireland and on the internal dimensions of the Northern Ireland problem.4 When Boris Johnson replaced May last July as Prime Minister, he promised to review the Brexit deal. Last week, it reached an agreement with the EU.