It hardly seemed credible.

Drone after drone, emerging from the top of a shipping container parked by the side of an unremarkable road somewhere deep inside Russia.

Each tiny device buzzed as it rose laden with explosives on its kamikaze mission to destroy some of the Russian military’s most prized assets.

As they flew overhead, filming their progress, their targets came into view: rows of strategic bombers, some capable of carrying nuclear weapons.

Ukraine’s domestic intelligence agency, the SBU, said it was responsible for the attacks on four bases, and a security official said a total of 41 Russian warplanes worth some $7 billion were hit.

Credit: Telegram / russianocontext

The attack comes at a critical juncture in the war, with Donald Trump’s peace plan hanging by a thread.

But the extraordinary story of how the drones were deployed to launch their attack started many months earlier.

Over a period of weeks, they were smuggled into Russia under the supervision of the SBU, which presumably had to alter its targeting plans after Russia relocated the bulk of its strategic bomber fleet.

The drones were then concealed inside special containers placed inside commercial cargo lorries whose roof panels had been modified to retract at the touch of a remote control button.

By all accounts, the drivers had no idea about the nature of the dangerous cargo they carried.

Local residents near the Olenya base in Russia’s far north described watching a driver running around in panic as FPV drones repeatedly launched from the back of his lorry.

He later told police that he had been instructed to park his vehicle in a lay-by near the town of Olenegorsk where somebody would meet him.

Footage from elsewhere in Russia showed drones rising from the back of another lorry as passers-by stood by helplessly.

It was not the first time that lorries had been used by the Ukrainians in the war.

A truck carrying explosives was remotely detonated to help bring down part of the Kerch Bridge connecting Crimea to the Russian mainland in 2020.

But this was rather more sophisticated, with reports that the drones had been trained using artificial intelligence to hit the weakest points of the bombers parked along the aprons of the airbases.

Fearing Ukraine’s growing strike capacity, Russia had only weeks earlier moved many of its strategic bombers to bases like Olenya and Belaya, 1,000km and 2,500km from the front line, where it was assumed they would be well beyond the enemy’s reach.

Other bases in Ryazan and Ivanovo were also targeted, both of which are within 600 miles of the Ukrainian border.

For the Russian air force, the planes targeted were prize assets: the iconic Tupolev Tu-95 “Bear”, a long-range strategic bomber capable of carrying both nuclear and conventional warheads; the Tu-160 “Blackjack”, the largest combat aircraft in the world, and the Tu-22M3 “Backfire”, the supersonic strike workhorse of the fleet.

The Russians, however, had not counted on Ukraine’s Mossad-like ingenuity nor their desperation to strike at the long-range bombers that had inflicted so much destruction and bloodshed on its cities and people.

For the most part, Operation Spider Web, as it has been designated, did not rely on long-range drones or missiles, but instead on small, hand-held first-person view drones of the kind that has proved so effective on the battlefield.

Russian military bloggers were quick to liken it to the Japanese surprise attack on Pearl Harbour in 1941.

An exaggeration, clearly — yet in terms of chutzpah, in terms of scope and quite possibly in terms of damage, Ukraine’s near-simultaneous attacks on four airfields deep inside Russia marks an unprecedented moment in the war.

If Ukrainian officials are to be believed, as many as 40 of Russia’s most sophisticated, expensive and destructive strategic bombers were eliminated in little more than a couple of hours.

Such claims await the confirmation of an independent battle damage assessment, yet whatever the real number is there can be little doubt what a humiliating blow Ukraine has inflicted on Russia – or what a powerful message Kyiv has sent its allies in the West.

For night after night before the surprise assault, Ukraine’s cities had reeled under some of the most intense Russian bombardment of the war. Dozens had died, children among them, yet there was no sign of the Kremlin relenting.

As his envoys prepared to present his peace terms at a second round of negotiations in Istanbul, Vladimir Putin seemed determined to project Russia’s total military dominance. So confident does he remain that his forces will prevail on the battlefield that the Russian president contemptuously ignored requests to share his proposals with Kyiv in advance.

Yet hours before the talks were due to begin, Volodymyr Zelensky, the Ukrainian leader, had a pointed message of his own to deliver.

He had been involved in Operation Spider Web from its conceptualisation 18 months ago. There had been coordinated attacks on Russian airfields before. On the night of August 13 last year, Ukraine unleashed what was then its largest drone assault of the war on Russian territory, striking four airbases in Kursk, Voronezh and Nizhny Novgorod. Yet these bases were all within a few hundred miles of the Ukrainian border.

Operation Spider Web was conceived on a much, much grander scale.

On the night before it was initiated, Ukraine had suffered perhaps its most intense airstrikes of a bloody week, with officials in Kyiv saying that 472 drones and seven ballistic and cruise missiles had struck targets across the country, including the capital.

By Sunday morning, Ukraine appeared to have exacted a measure of revenge after two transport bridges were blown up in the neighbouring regions of Bryans and Kursk just as trains were passing. Seven people were killed, Russians officials said, blaming Ukraine.

Yet these attacks were but a prelude.

Among the planes destroyed, Ukrainian intelligence officials said, were not just Tu-95 and TU-22M3 bombers but also an A-50 “Mainstay”, one of just a handful of Airborne Early Warning and Control aircraft Russia has left in its arsenal. The A-50, worth an estimated £230 million, is a flying radar and command post that is vital for coordinating fighter jets and air defences as well as for situational awareness. They are thought to be irreplaceable.

According to Ukrainian intelligence officials, all those knowingly involved in the operation have returned safely home, their mission accomplished in the most astonishing way.