The UK may be the only member-state to activate article 50, but it is not the first country to seek to leave the EU. Algeria left in 1962, Greenland in 1985, and St Barthélémy in 2012.

None of them shared a land border with the EU and the 499 kilometres of the Irish border presents a far greater challenge. But there are precedents from these previous exits and the EU’s current land borders that might point to a solution?

In each previous withdrawal, sovereignty, or a perceived lack of it, played a key part in calls to leave the EU. Algerian president Ahmed Ben Bella decried “300 years of colonial domination” after independence from France. Prior to Greenland’s referendum in 1982, prime minister Jonathan Motzfeldt praised Greenland’s special mix “of language, culture, economy and social structure” which required freedom from Brussels, “in order to preserve the peculiarity of the country”.

That “peculiarity” is far easier to maintain, however, when borders are uncomplicated. This certainly does not apply to the Russian city of Kaliningrad, a land area, smaller than Wales, and bordered by Poland to the south and Lithuania to the north. With the latter’s 2004 accession to the EU rendering it impossible for the oblast’s 955,000 Russian citizens to travel between Kaliningrad and the rest of Russia without requiring a visa, a workable solution was required.

Visa-free travel

Negotiations concentrated on Russian demands for visa-free travel, with President Putin arguing that an EU refusal would represent a “rejection’’ of what he felt was Russia’s “European choice”. The EU eventually compromised in the form of the special “Facilitated Transit Document”, the equivalent of a multi-entry visa. Issued by Lithuanian consulates to Russian citizens travelling frequently between Kaliningrad and the rest of Russia, this practical solution sufficiently placated Moscow.

The spectre of boundary fences and watchtowers, present at Kaliningrad’s border checkpoints, has been a constant of the Brexit debate in this island. Whatever happens on the border on this island, this example of the EU’s accommodation with Russia exemplifies its ability to deal constructively with neighbours despite substantial political tension.

As we see with the autonomous cities of Ceuta and Melilla, Spanish exclaves on Morocco’s northern coast, the EU adapts its approach on border protection to specific circumstances. Control over migration is the raison d’etre of the 19-foot-high fence, watchtowers and kilometres of razor wire surrounding the territories. In 2018, 14,680 migrants arrived in Spain, while approximately 7,000 migrants illegally entered Ceuta and Melilla. However, Moroccan citizens from adjoining provinces can apply for a permit that effectively renders the holder exempt from visa requirements, an initiative intended to prevent the complete partition of Ceuta and Melilla from the surrounding areas.

Trade and immigration

Sovereignty infers control, and arguably the most pressing issue for Brexiteers has been the need to “take back control” of areas such as trade and immigration. Similarly, these played a substantial part in previous post-exit withdrawal negotiations. Greenland was pulled into the EU by Denmark in 1972, despite 70 per cent of its inhabitants voting against accession due to suspicions of the EU’s Common Fisheries Policy. A subsequent leave majority in a referendum of 1982 prompted three years of withdrawal negotiations.

Talks focused almost solely on the fishing industry and culminated, in the words of Greenland’s lead negotiator, Lars Vesterbirk, in little change. “British people should always remember that the EU was created for the benefit of member states, not for those outside; you don’t get anything without giving something in return,’’ Vesterbirk noted.

For Saint Barthélémy, (an overseas collectivity of France located in the Caribbean, often known as St Barts) where customs and competition rules were believed to put the island at a disadvantage relative to competitors’ more open regimes – control over customs and, importantly, migrant labour was crucial to withdrawal arguments.

Overseas Territories

Proponents of Brexit have regularly referred to a “Hotel California” scenario in which Britain can “check out” of Europe, but ultimately never leave. Happy to exist in this liminal space, Greenland and Saint Barthélémy have established themselves as Overseas Territories and retain many of the benefits of that close relationship with the EU.

As Taoiseach Leo Varadkar recently intimated to British prime minister Boris Johnson that there can be no “clean break” Brexit. Physical borders and political relations between territories are liminal spaces where the strictures of internal coherence meet the practicalities of the need for commerce and communication.

Negotiating this space requires give and take on both sides. The policies and practicalities of the EU’s external borders show that the EU has experience in navigating this difficult and uncertain terrain. Who knows where Brexit may yet eventually lead on this island, but it will not be for lack of willingness to search for workable alternative solutions.

Noelle O’Connell is the Executive Director of European Movement Ireland