- The UK MOD said Russia tried to create elite "storm" units in Ukraine, but they were largely ineffective.
- It said they were full of convicts and were sent to attack with little support.
Russia tried to build up its "Storm Z" units as an elite fighting force but instead pivoted to stuffing them with convicts and other low-quality fighters, UK intelligence said.
The units instead became a symbol of Russia's struggle to field any units capable of mounting an effective offense, the assessment said.
The UK Ministry of Defence said in its intelligence update on Tuesday that Russia probably wanted the Storm Z units — sometimes styled as Shtorm-Z — to be "relatively elite organisations which could seize the tactical initiative."
Instead, it said, they had "effectively become penal battalions, manned with convicts and regular troops on disciplinary charges."
This tallies with reporting that suggested soldiers had been sent to such battalions as punishment — one man described this happening in an interview with Reuters.
Despite the units' shortcomings, the MOD said, Russia was still relying on them for local offensive operations in Ukraine.
The use of prisoners in storm units of Russian convicts has previously been reported, including by the Institute for the Study of War, which said in September that the units had been sent to a region of heavy fighting, presumably to act as "cover" in case elite units needed to retreat.
Fighters in the units and people with knowledge of them told Reuters this month that soldiers in storm units were seen as disposable.
A soldier in a regular army unit said he was instructed not to treat injured storm-unit soldiers. "Storm fighters, they're just meat," he told Reuters, adding that he disobeyed the instruction not to help them.
One Storm-Z group of fighters said in a video in June that they would not obey orders to go back to the front line and alleged they were not given food, water, ammunition, or medical care, Reuters reported.
The UK update said the storm units seemed to be sent to heavy fighting with little help from Russia: "Multiple accounts suggest the units are given the lowest priority for logistical and medical support, while repeatedly being ordered to attack."
The MOD said Russia's struggles with building storm units showed the trouble it was having with building up an effective infantry, though its troops "often conducted an effective defence."
"The existence of Shtorm-Z highlights the extreme difficulty Russia has in generating combat infantry capable of conducting effective offensive operations," the MOD said.
Reports and Western intelligence have also pointed to Russia's struggle to staff and direct its military since it launched its full-scale invasion of Ukraine in February 2022.
This includes relying on prisoners to replenish its fighters and seeing once-elite units being degraded by new members without any significant training.