If you read the papers as religiously as I do, it feels as though the Union is under attack almost every day. Scottish devolution gave nationalists a permanent redoubt. When they lose, they can retreat, regroup, rally the faithful and, with Holyrood’s administrative machinery, become almost unkillable. Westminster and the English taxpayer effectively underwrite the nationalist base from which the assault on the Union can be repeatedly mounted.
This was not inevitable. Unionists repeatedly warned that a Scottish Parliament would be turbocharged toward separation, and that it was desperately naïve to imagine it would somehow “dampen” or kill off nationalism. Labour leaders of the late 1990s believed the opposite. George Robertson’s prediction that devolution would “kill nationalism stone dead” captured the calculation: create a Scottish satrapy forever under Labour suzerainty and the threat would wither. The calculation was dead wrong. Within eight years Scottish Labour had lost Holyrood to the SNP. Once the nationalists held the whip hand they used it ruthlessly, turning the devolved institutions into a permanent battering ram against the United Kingdom.
The constitutional changes of the Blair era compounded the problem. The expansion of judicial review, the elevation of the courts over Parliament and the rise of the professional expert class have left successive governments fighting little more than occasional rearguard actions in defence of the Union. The Good Friday Agreement, whatever its honourable intentions, locked in mechanisms that keep Northern Ireland’s place in the UK permanently contested. Wales remains at an earlier stage of the same playbook: Plaid Cymru campaigns on bread-and-butter issues and keeps the independence mantra quiet for now. Last week the leaders of the three Celtic nationalist parties signed a memorandum of understanding. Notably it was the party leaders, not the first ministers. Parties and movements outlast governments.
Yet the Union is far from doomed.
In the Republic of Ireland a united Ireland barely registers among public priorities. In poll after poll it scrapes in at around 2 per cent, far behind housing, the health service and immigration. Ireland’s economic model depends heavily on American investment and goodwill; roughly one in five jobs is linked to US companies. Instability, or a deliberately combative Sinn Féin-led government picking fights with the United Kingdom, would carry costs Dublin cannot ignore. Both parts of the island would still have to consent. In Northern Ireland the gap between those favouring the status quo and those favouring unity has narrowed to roughly six points (around 42 per cent to 36 per cent in the latest Life & Times survey), yet middle-ground voters would still have to weigh the loss of the NHS, UK pensions and fiscal transfers against uncertain benefits. No British government will easily persuade English taxpayers to fund Northern Ireland’s exit while continuing to underwrite its public services.
The external environment has shifted further against frictionless secession. Scotland contains assets of first-order importance to the United Kingdom and to NATO: the nuclear deterrent base at Faslane and Coulport, RAF Lossiemouth, shipbuilding and munitions capacity on the Clyde, North Sea energy infrastructure and a long coastline that would become an independent state’s exclusive economic zone. A small newly independent Scotland — even one that rejoined the European Union — would present a more vulnerable target for Russian and Iranian pressure. NATO and the United States have a direct interest in keeping the northern approaches and the continuous at-sea deterrent under reliable, integrated command. American misgivings would carry weight inside Scotland itself: the Clyde yards and the wider defence industrial base are large employers whose future would become uncertain the moment the Union was broken.
Spain remains an obstacle. Madrid has made clear it would treat any Scottish application as a new accession under ordinary rules, a process that would set a precedent Catalan or Basque nationalists could exploit. EU membership is far from guaranteed. A united Ireland would create parallel difficulties. The Republic has essentially no navy or air force and relies on arrangements with the UK to protect its airspace and maritime waters. Critical transatlantic undersea cables land on the island of Ireland; their physical protection becomes harder when the United Kingdom loses its residual presence and when a shared state no longer underpins security cooperation. Sinn Féin’s political tradition remains deeply sceptical of NATO and of British military power. Dublin, with Sinn Féin in government, would prioritise neutrality over defence.
None of this is theoretical. British defence policy has already adjusted. The Integrated Review and its refresh, the AUKUS partnership and the renewed focus on the North Atlantic and High North all reflect a recognition that the maritime approaches, undersea infrastructure and nuclear posture cannot be treated as optional. Allied capitals share that assessment. The question of Scottish independence or Irish unification is therefore no longer solely a domestic constitutional argument. It is becoming a question of realpolitik: alliances, security and the defence of the western flank in an increasingly contested world order.
Devolution gifted structure, income and status to the enemies of the Union. Nationalists can still pull on the emotional strings of a polarised and less historically literate electorate. World events, however, are throwing up potentially insurmountable barriers. Irish public opinion refuses to treat unification as urgent. English taxpayers will not readily underwrite Northern Ireland’s departure. The United States and NATO remain heavily invested in the UK holding the northern and western flanks and protecting the transatlantic cables. Scotland’s last major industrial communities are tightly bound to the defence sector; jobs beat Braveheart when the mortgage is due.
Three hundred and nineteen years on, the Union still stands. Its survival depends less on sentiment than on whether these hard constraints continue to outweigh the institutional advantages devolution gave its opponents. At present, the price of breaking it remains high — and rising.