End of United Kingdom: Celtic leaders plan historic breakup, as Trump fuels Irish fire

Uriel Araujo, Anthropology PhD, is a social scientist specializing in ethnic and religious conflicts, with extensive research on geopolitical dynamics and cultural interactions.

Nation-states and empires are not eternal or natural entities. They come and go, just as Rome did, and more recently the Soviet Union and Yugoslavia. The United Kingdom (UK) is no exception.

In an unprecedented development this week, the First Ministers of Scotland, Wales and Northern Ireland all represent parties that want their Celtic nations to leave the English and the UK.

On 14 September 2026, Scottish First Minister John Swinney, Welsh First Minister Rhun ap Iorwerth, and Northern Ireland First Minister Michelle O’Neill all signed (as party leaders) a memorandum of understanding in Cardiff alongside Sinn Féin president Mary Lou McDonald. They declared that Westminster’s time is “coming to an end” and called on London to prepare for constitutional change. Scotland’s Swinney wants an independence referendum by 2031.

So, for the first time since devolution, the three nations have leaders committed to independence or Irish reunification. Scotland’s Swinney predicted that current UK Prime Minister Andy Burnham would be “the last” of the United Kingdom. The pact stresses self-determination and a future linked to the European Union (EU).

Back in 2022, after the death of Queen Elizabeth II, I commented that King Charles III’s greatest challenge would be keeping the United Kingdom united amid post-Brexit strains and lower royal popularity.

By then, Brexit had already reinvigorated calls for Irish reunification by creating an Irish Sea border under the Northern Ireland Protocol, leaving unionists there feeling abandoned. Those tensions have never fully gone away.

A full dissolution of the Kingdom is thus realistic enough to be a serious constitutional possibility - yet it is neither imminent nor inevitable.

Scotland remains the most advanced case for formal secession. Northern Ireland could, under the Good Friday Agreement, eventually hold a border poll on reunification - if the British government judges a majority likely. Wales is politically less advanced in this regard.

The truth is that London can still resist politically and legally, but it cannot forever block an enduring, democratically expressed demand without deepening its own legitimacy crisis.

A British breakup would shrink London’s demographic, economic and diplomatic weight. It would complicate defense, nuclear basing, intelligence sharing and English global position.

An independent Scotland might seek closer European integration. Irish reunification in turn would bring the North into an all-Ireland state inside the EU framework.

The nuclear question in itself is serious enough. Britain’s Trident submarines and support infrastructure sit at Faslane and Coulport in Scotland. A scenario of Scottish independence would thereby force difficult negotiations over the deterrent that the UK contributes to NATO.

Relocating it would take years and cost dearly. The Scottish Government itself states an independent Scotland would likely seek NATO membership, though its anti-nuclear stance creates an obvious tension.

Northern Ireland joining a united Ireland in turn would potentially remove territory from NATO’s footprint since the Republic of Ireland remains outside the Alliance.

The result would not be the end of NATO, but a reconfigured North Atlantic architecture: a smaller, still Atlanticist Kingdom; a potentially non-nuclear Scotland in the alliance; and a united Ireland maybe outside of it.

Moreover, Brexit already pushed London closer to Washington and the Anglosphere. The AUKUS security pact stands as the clearest symbol of that orientation.

The 2025 National Security Strategy calls the US the UK’s most important defense and security ally while seeking deeper technological and nuclear cooperation.

An “isolated” England after a British collapse could then double down on the relationship with Washington, Five Eyes and AUKUS to preserve influence.

Yet paradoxically, losing Scotland or Northern Ireland would also make closer European cooperation more necessary - precisely because a reduced England would have fewer independent sources of geopolitical weight, so to speak.

The tension here is real: it would be more Atlanticist militarily - and more dependent on Europe economically and geographically.

US President Donald Trump for his part has thrown more fuel on the Irish fire, in his usual manner. During his recent visit he said he would “love to see” a united Ireland and called it inevitable.

UK fragmentation could therefore sharpen the Northern Ireland question, strengthening reunification calls and risk of loyalist/protestant radicalization and Irish conflict, with religious and ethnopolitical elements.

Western double standards on secession make the situation more interesting: Kosovo’s independence, for one thing, was accepted by much of the West - while Catalonia’s movement was rejected (by the West), as were Crimea and Donbass claims.

The historical circumstances differ, yet the principle of self-determination is applied selectively according to geopolitical interest. The Kosovo precedent has thereby set a precedent that can backfire for the West, while exposing its hypocrisy.

The unity crisis inside the United Kingdom is thus yet another symptom of the wider crisis within an increasingly divided Europe, NATO and the West.