In a military campaign marred by logistical troubles and dwindling morale, it's fair to say Vladimir Putin's "special operation" in Ukraine hasn't quite gone to plan.
Thanks to a handful of miscalculations, analysts say Russian forces have largely abandoned their original objective of a large-scale occupation in favour of cementing their hold on the eastern Donbas region.
Given the sheer size and scale of Russia's firepower, some of these missteps have been seen as particularly humiliating for the leader who prides himself on his military might.
Mr Putin poured $US65 billion ($93 billion) into boosting his defences in 2019, almost 4 per cent of Russia's GDP.
And while Russia's budget and troop numbers pale in comparison to major Western powers like the US, it still dwarfed Ukraine's capability at the beginning of the war.
But Volodymyr Zelenskyy's forces, bolstered by conscripts and volunteer soldiers, appear to have beaten the odds on several occasions.
Perhaps the earliest embarrassment for the Russian forces came on the very first day of fighting, in what would go on to become a parable of Ukrainian resistance.
The battle for Snake Island
Hours after Russia sent its troops over the border and began air strikes targeting major cities on February 24, border guards on a small island 300 kilometres west of Crimea received a message.
"This is a Russian warship. I suggest you lay down your weapons and surrender to avoid bloodshed and needless casualties. Otherwise, you will be bombed," the officer warned.
Communications were cut off and Ukrainian authorities initially believed the 13 border guards on Zmiinyi (Snake) Island had been killed trying to defend their rocky outcrop.
But days later, several of the Ukrainians were spotted on Russian TV, held captive by Russian forces in Sevastopol.
Within a month, they had been freed as part of a prisoner exchange and returned to a hero's welcome.
Roman Hrybov's slogan now adorns everything from postage stamps to tote bags.
"I don't know how he did it but my son conquered the world with his slogan … he raised the spirit of the people to fight against the occupier," Hrybov's mother Tetyana told BBC podcast War on Truth.
In the meantime, Snake Island itself has become not just a symbol of resistance but of Russia's paper tiger of a military.
It proved to be quite the strategic prize in the ongoing war, nestled between Romania, Odesa and the Crimean peninsula, with its maritime borders extending well into the resource-rich Black Sea.
Ukraine, with the help of military equipment sent by its Western allies, fought fiercely to win the island back, determined to block Russia from establishing a defensive base.
On April 14, Ukrainian officials claimed a hefty scalp: the Moskva, the very same Russian missile cruiser that had approached the island on the first day of the war.
Russian officials claim the warship sank after an accidental fire.
In either case, the jewel of Vladimir Putin's Black Sea fleet is now resting at the bottom of the ocean while Ukraine's best fighter jets continue raids on those forces still occupying Snake Island.
Satellite images from last week show another Russian boat fleeing the area under missile attack, and recent photos show significant damage to several buildings on the island.
"Whoever controls the island can block the movement of civilian vessels in all directions to the south of Ukraine at any time," Ukrainian defence intelligence chief Kyrylo Budanov said on May 13.
"Zmiinyi Island is Ukraine's territory, and we will de-occupy it and we will fight for it for as long as it takes."
All the dead generals
When Russia's invasion of Ukraine faltered in the first days, senior commanders were rushed to the front in a desperate bid to keep up momentum.
But by dispatching his most senior generals to the battlefield, President Vladimir Putin left them vulnerable to Ukrainian snipers and artillery units.
"Those commanders are trying to impose their own personality on the battlefield but this, in turn, is placing them at greater risk," BBC security correspondent Gordon Corera said.
The first confirmed death was Major General Andrey Sukhovetsky, who was killed by a sniper just four days into Russia's war.
Two more senior officers, Lieutenants General Yakov Rezantsev and Andrei Mordvichev were also reportedly killed in separate attacks on the Chornobaivka airbase.
Ukraine claims to have killed 12 Russian generals.
Russia has only confirmed two deaths, while Western officials believe about seven generals have been killed in fighting since the war began.
The US has admitted to providing intelligence that has helped Ukraine target and kill Russian generals.
But experts are quick to point out that Russia's top brass are not exactly hard to find when they use an iPhone or push-to-talk radio to communicate.
"We're seeing them use a lot more unclassified communications because their classified communications capability … for one reason or another, is not as strong as it should be," a US defence official told reporters in March.
As well as having a huge impact on morale in the Russian military, the deaths of generals leave a power vacuum at the top.
"Every death of a general makes the Russian Armed Forces less effective," independent military analyst Pavel Luzhin told The Moscow Times.
"It can take days or even weeks to replace them."
The failed river crossing in Donbas
In what might be its greatest disaster on the battlefield, Russia recently lost almost an entire battalion in a botched attempt to cross a river in Ukraine's east.
It all started when Russian forces, desperately trying to squeeze out a victory for Vladimir Putin in the Donbas region, tried a tricky manoeuvre to surround the twin cities of Lysychansk and Severodonetsk.
But the sneak attack required the battalion to cross the Siverskyi Donets River with a pontoon — a floating bridge that would allow the armoured vehicles and troops to cross over.
The Ukrainian forces, however, had been lying in wait.
It is believed a local tank brigade noticed the Russian soldiers near the river and instructed nearby artillery and aircrews to get ready.
When Russian forces lit fires in nearby fields and forests to obscure what they were doing, Ukrainian troops knew they would be on the pontoon and completely vulnerable.
A series of air strikes decimated the battalion.
A Ukrainian explosive ordnance disposal officer named Maxim claimed on Twitter to have coordinated the attack.
"In 20 minutes after [the reconnaissance] unit confirmed the Russian bridge [was] being mounted, heavy artillery engaged against Russian forces, and then aviation chipped in as well," he said.
"I was still in the area, and I have never seen … such heavy combat in my life."
More than 70 tanks and armoured vehicles are believed to have been destroyed and up to 1,000 Russian troops were killed.
"Conducting river crossings in a contested environment is a highly risky manoeuvre," the UK Defence Ministry said of the incident.
"[The manoeuvre] speaks to the pressure the Russian commanders are under to make progress in their operations in eastern Ukraine."
Many military experts believed Russia would fare better in the Donbas because they tend to be more comfortable fighting on flat plains where they can encircle the enemy.
While they have made some gains, the US Department of Defense said the eastern offensive is not going as well as Vladimir Putin hoped.
"We still assess the Russian ground force in the Donbas to be slow and uneven," a senior official told reporters on May 10.
Overall, there has been a "notable decline in energy" in Russia's advance, according to the Institute for the Study of War.
"Russian offensives have bogged down every time they hit a built-up area throughout this war, and these areas are unlikely to be different," the Washington-based think tank said.
"Continued and expanding reports of demoralisation and refusals to fight among Russian units suggest that the effective combat power of Russian troops in the east continues to be low and may drop further."
