Here we are again. The Treasury, that dreary bastion of actuarial pessimism, has dusted off its most alarming spreadsheets to model the fiscal apocalypse of a war with Iran. A 0.3% contraction. A pittance, they call it. A manageable risk. But anyone who has read Gibbon knows that empires do not collapse in a single thunderclap. They rot from within, decimal point by decimal point, until the barbarians are at the gates and the treasury is empty.
Let us be clear: a war with Iran would not be a repeat of Iraq or Afghanistan. Those were colonial policing actions, messy and expensive but ultimately contained. Iran is a different beast: a theocratic state with regional proxies, a capable military, and a chokehold on the Strait of Hormuz. The Treasury’s models assume a short, sharp shock. They assume that oil prices will spike, then settle. They assume that the City will tut, adjust its portfolios, and move on. This is the optimism of the accountant, not the historian.
Consider the Victorian era. Britain fought the Crimean War, the Boer War, a dozen colonial skirmishes. Each was financed by debt, each was deemed necessary for the preservation of empire and trade. And each left the nation a little weaker, a little more dependent on the goodwill of foreign creditors. By 1914, the Treasury was still running on Victorian assumptions. War with Germany would be swift, they said. The boys would be home by Christmas. We know how that ended: with a generation dead, the pound sterling dethroned, and the empire’s death warrant signed.
Today, the UK is a shadow of that imperial power. Our economy is service-based, reliant on financial flows that evaporate at the first sign of geopolitical instability. A war with Iran would not just spike oil prices. It would trigger capital flight, a run on the pound, and a crisis of confidence in British sovereign debt. The Treasury’s 0.3% contraction assumes that the world will carry on buying our gilts while we bomb their energy supplies. That is not modelling. That is wishful thinking.
And what of the intellectual decadence that permits such folly? We have become a nation of technocrats, fluent in spreadsheets but deaf to the lessons of history. The fall of Rome was not caused by a single battle or a barbarian invasion. It was the cumulative effect of overextension, fiscal mismanagement, and a ruling class that believed its own propaganda. Sound familiar? Our leaders speak of global Britain, of punching above our weight, while the national debt approaches 100% of GDP. A war with Iran would not restore our standing. It would accelerate our decline.
The Treasury’s models do not account for the unpredictable. They do not model the closure of the Strait of Hormuz, the disruption of global supply chains, the refugee flows, the terror attacks on home soil. They do not model the psychological impact on a population already exhausted by austerity, pandemic, and inflation. They do not model the moment when the markets decide that Britain is no longer a safe bet. That moment, when it comes, will not be gradual. It will be a cascade.
We are living through the end of an era. The post-war consensus, the American security guarantee, the cheap energy that fuelled our prosperity: all are fraying. A war with Iran would be the final act of a dying empire, a desperate grasp at relevance. The Treasury can model all it likes. It cannot model away the reality that we are a nation living beyond its means, led by politicians who mistake spreadsheets for strategy.
So let us pause before we march to war. Let us ask not whether we can afford a 0.3% contraction, but whether we can afford any contraction at all. The Romans did not see the end coming. They were too busy counting their sesterces. We have the advantage of hindsight. The question is whether we have the wisdom to use it.
