Vladimir Putin may be mocked as a pound shop Napoleon, but his attempts to cut the cost of his war on Ukraine have changed the face of modern warfare.

While Donald Trump bombs Iran with billions of dollars worth of high-tech cruise missiles, in Ukraine, Russia has switched to home-made budget versions, used at scale, with devastating results.

Enormous missile and drone swarms are overwhelming defences and bombarding cities across the country, offering a horrifying insight into how Russia could fight a war – if it ever came to it – against Nato.

Now it is mass and scale that matter – an approach which until recently, the West had sidelined in favour of fewer, more exquisite systems. Russia has had four years of learning adversaries’ weaknesses – and how to overwhelm their defences.

Russia’s cruise missile tactics

One of Putin’s most effective weapons during the war in Ukraine is the Banderol hybrid cruise missile, which uses a $16,000 (£11,830) off-the-shelf Chinese engine and – concerningly – multiple components from nations that sanction Russia such as the US and Australia. Estimates of the total price of a Banderol range from $50,000-$100,000 (£36,970-£73,940).

Meanwhile a UK Storm Shadow – as supplied to Ukraine – costs between $1m (£0.74m) and $2.5m (£1.85m) depending on the variant, and a US-made Tomahawk cruise missile costs upwards of $2m (£1.48m).

Storm Shadows travel faster – 950kph to the Banderol’s 600kph, and pack a bigger punch – 450kg warhead to the Banderol’s 150kg. But they have almost exactly the same range, and the levels of terror they can inflict are similar to those on the receiving end – especially as 20-40 Banderols can be built and launched for the price of one Storm Shadow or Tomahawk.

The Banderol is cheap, fast and carries a high-explosive fragmentation warhead. The weapon has formed a key part of Putin’s strategy to try to choke Ukraine’s maritime trade by making it too perilous for cargo ships to pass through the waters around the Black Sea ports of Odesa, Chornomorsk and Pivdennyi.

It’s easy to see why a Putin juggling a budget deficit that has more than doubled in a year, out of control inflation, and crippling fuel prices would find the Banderol such an attractive proposition in such an expensive war.

Cheap, deadly swarms

Military experts agree that using low-cost weapons at scale will define not just the Ukraine conflict but the future of war, as mass attacks overwhelm and confound even the most advanced defence systems.

A recent strategic assessment document for Nato’s Transformation Command reads: “Mass is no longer an armoured column moving across a field; mass is now a distributed swarm of real-time command decisions executed via thousands of cheap aircraft. We are entering a phase where the side that can manufacture disposable digital attrition fastest wins the day.”

And on the ground in Ukraine, drone commander Colonel Yuriy Solovko said: “The Pentagon is still thinking in terms of multimillion dollar exquisite platforms that take 10 years to build. Out here, a $500 (£370) FPV drone with a taped-on RPG warhead defeats a $10m (£7.4m) main battle tank. We don’t need exquisite; we need numbers.”

Michael Clarke, visiting professor in the Department of War Studies at King’s College London, said that the “sheer numbers” of drones and cruise missiles produced cheaply in the conflict was a vital tactic for both Moscow and Kyiv.

“The cheapness of drones and cruise missiles means that any defence can be overwhelmed by sheer numbers and you wouldn’t have said that necessarily five years ago,” he said.

“That’s what’s new is that we’re looking at the possibility of mass bombing, not by aircraft flying over the territory and dropping bombs, but by literally swarms of drones, backed up by cruise missiles, with ballistic missiles following them in, which simply punch through any defence you can put up and that’s a real challenge.”

Russia produces a range of Iran-inspired Geran drones, from the original, no-frills model to the most advanced jet-powered Geran 4, which can travel at speeds of up to 400kph. They are fired en masse, making it difficult for them to be intercepted. In August, 2,500 jet drones were fired into Ukraine. The unit cost for a Geran-4 is estimated at $50,000 (£36,970).

Emily Ferris, senior associate fellow at UK defence think-tank Rusi, said there was nothing “hugely innovative” about the technology Russia was developing, but the way the weapons were being deployed was revolutionary.

She added: “It does seem that they’re still trying to use mass and volume to overwhelm the Ukrainians, rather than sort of innovation, which is why the war is being fought slightly differently by both sides.”

Mark Galeotti, an author and expert on Russia, said: “One of the things that this war really has demonstrated is that mass, or scale, matters, that you need not just to have a handful of exquisite systems, which has always been the West’s approach.

“That’s all very well, but sometimes you just need to throw loads of weapons at the enemy, and so that that’s what we’re seeing now.”

Russia is learning how to fight the West

The use of cheap, mass-produced munitions in swarm attacks could be adapted to threaten Western defences.

Experts are fearful that Russia is using the war in Ukraine to probe Nato’s weak spots and gather intelligence for a future conflict.

One unnamed senior Nato official in June told the UK Defence Journal that the war in Ukraine was “no longer just the regional war” but had become “a global learning environment” for the likes of Russia and China.

“If our adversaries can observe, adapt, and scale faster than we can”, then the advantage of Nato’s capabilities would be reduced over time, they said.

Ferris said: “There’s kind of a broad assessment that however this current war ends, Russia is likely planning ahead for the next kind of confrontation with the West.

“The question is how well Russia applies those lessons. If you look at previous conflicts that Russia has been involved in, sometimes those lessons are applied pretty well afterwards, and sometimes they’re really not.”

The trail of wreckage across Ukraine left by Putin’s bargain-basement bombs serves as a vivid warning.