The two explosions came decades apart but both in the dead of night. The first, at 1:23 a.m. on 26 April 1986, scattered radioactive graphite across Europe and shook the Soviet system to its foundations. The second, at 1:59 a.m. on 14 February 2025, was delivered by a Russian drone that tore through the polymer shell of the New Safe Confinement – the immense arch slid over Reactor Four in 2016 and designed, its French-led consortium insisted, to withstand tornadoes, earthquakes and a century of slow decay. Engineers in the control rooms beneath the stricken sarcophagus now monitor a structure already compromised, with repair costs estimated at half a billion euros. Viewed from Kyiv, what once seemed unthinkable – a deliberate strike on the site that symbolises Ukraine's inherited suffering – has become another front in a war that respects no red lines.

Forty years on, the catastrophe retains its hold on the region's body and memory. In the days after the initial blast, the Soviet apparatus did not inform its citizens but hunted for American spies and Ukrainian nationalist infiltrators; declassified KGB files record the regime pressuring diaspora organisations that sought to help the wounded. Across the border in Belarus, which absorbed seventy per cent of the fallout, families still taste metal in their mouths on certain spring mornings. In the Mogilev region, children continue to travel to Quebec each summer under a charitable programme that has run for decades – their internal radiation levels dropping by a third or half after weeks of clean air and uncontaminated food, a quiet testament to the disaster's relentless biological half-life.

Yet from this poisoned landscape a strange paradox has emerged. The 2,800-square-kilometre exclusion zone has become one of Europe's largest nature reserves, a rebuke to humanity's custodianship of its own territory. The animals that roam there – elk, wolves, Przewalski's horses – know nothing of the dosimeters clicking in the hands of the technicians who still enter the zone. The reactor roof itself became a graveyard for technological hubris in 1986, when Soviet, German and Japanese robots sent to clear highly radioactive debris all failed, their circuits fried by radiation levels off the scale of their designers' imagination. Humans had to do the work after all, in ninety-second sprints across the graphite-strewn concrete.

Analysts in London and Washington note that the geopolitical moment is reshaping the nuclear question that Chernobyl seemed to have settled. More than four hundred reactors operate in thirty-one countries today, with seventy under construction. Germany and Italy, which shut or shelved their nuclear programmes after 1986, are now debating a return, driven by the energy insecurities exposed by war in the Middle East and the rupture with Moscow. Proponents point to smaller, cheaper, allegedly safer designs. Sceptics, particularly in Brussels and Vienna, observe that no engineering can fully account for the irrationality of a drone warhead or the collapse of the institutional vigilance on which all nuclear safety ultimately depends.

The forward picture is one of deepening tension between two realities. On one side, a global energy transition that increasingly treats nuclear power as indispensable – a low-carbon baseload source whose risks appear quantifiable and manageable. On the other, a security environment in which the unthinkable becomes operational with startling speed. The sarcophagus at Chernobyl was conceived as a monument to what had been learned. It now stands as a warning about what has been forgotten.