After failing to execute a plan to take Ukraine in a lightning fast operation, Russia's army has switched tactics to intensifying bombardment of Ukrainian cities, including reports of targeting a children's hospital in Mariupol.
The "special military operation" ordered by Russian President Vladimir Putin two weeks ago involved an assault on Ukraine by land, air and sea; attacking from three directions: from the south towards Kherson, from the north advancing to Kyiv and from the northeast aiming for Kharkiv.
But Mr Putin's original plan to take the capital of Kyiv quickly, in as little as 24 or 72 hours, did not eventuate.
Instead, satellite images released on Monday by US satellite imaging company Maxar Technologies show the convoy of Russian armoured vehicles has stalled 25 kilometres from Kyiv.
The tyres on the tanks have after being bogged down in the mud, exacerbating issues with logistics and supplies.
Mark Edele, a historian of Russia at the University of Melbourne, said what has been exposed is the lack of co-ordination among Russian armed forces, which means Mr Putin's invasion is not going as he originally planned.
"There's been a combination of very, very smart and careful tactics on the Ukrainian side, very determined both political and military leadership; and clearly poorly trained, poorly motivated and poorly commanded troops on the Russian side," he told SBS News.
"The Ukrainians have the advantage that they have internal lines of communications where they can redeploy forces relatively quickly. They have focused on basically trying to slow down the Russian advance by slowly trading space for time, that is having carefully, executed retreats — and hitting the supply lines of the Russian army."
The Russian army's convoy north of Ivankiv in Ukraine on 28 February 2022. Credit: Maxar Technologies
"Oh, it certainly is a David and Goliath battle. I mean, the Russian military is a million people give or take. The Russian forces, including their paratroop forces is around 350,000 regulars, not including their reserve forces. The Ukrainian military is nowhere near that size. But for all that, the Ukrainians have out-thought a much larger, and more technologically sophisticated, Russian military," he said.
US think tank the Atlantic Council says the logistics problems are now being remedied with rail deliveries of bulk supplies, and Russia will get back on track with its advance in the south, going for Mariupol and Odesa, and closing in on Kyiv from the north and the east.
"Over the next week, Russia will attempt cut the capital off and begin a brutal siege," military fellows from the council
What is Mr Putin's Plan B and Plan C?
Defence intelligence analyst Victor Abramowicz, formerly with the Australian Defence Force and now principal of Ostoya Consulting, said Mr Putin miscalculated by anticipating a quick and easy victory could be achieved with minimal resources.
"Not only has that not worked, but even as it rapidly started to not work, they haven't changed their strategy," he said.
"There are a multiplicity of reasons why that has happened. But probably the most compelling explanation is the Russian army just haven't properly trained and maintained their equipment.
"When you haven't trained and you haven't maintained and you haven't prepared properly, it's like going to the Formula One and expecting to win, but you've never had your pit crew working together, or you've never properly trained your driver. It's just going to be a disaster. And that's what seems to be happening."
Mr Putin had earlier said only professional soldiers were involved in the military operation, and there would be no use of military conscripts. The Russian defence ministry has now admitted conscripts were taken, saying some of them had been serving in supply units when they were taken prisoner by the Ukrainian army.
Dr Alexey Muraviev, an associate professor of national security and strategic studies at Curtin University, said that admission was very revealing.
"It is another demonstration on how — with at least with regards to the information front — the Russian political leadership haven't thought through this campaign. They didn't expect to have a protracted war. They expected a swift campaign," he said.
He said Mr Putin has now been forced to move to Plan C — fighting in the urban environment with the use of more aerial strikes, while also targeting the most experienced Ukrainian soldiers in the country's south and Donbas region.
The aftermath of the Russian invasion in the northwest of Ivankiv, Ukraine on 28 February 2022. Credit: Maxar Technologies
"And this is where you will also see the significant rise of human casualties because the civilians are caught in the middle of the fight in between the two opposing forces.
"And obviously the level of Ukrainian resistance made the Russians intensify the lethality of their strikes, the scale of their strikes to overpower that resistance."
The Kremlin insists the Russian army only targets military — not civilian — targets. The United Nations human rights office said it verified the deaths of at least 474 civilians in Ukraine since the fighting began on 24 February, adding the real figure is likely to be much higher.
How long is Mr Putin willing to wage a protracted war — and at what cost?
Mr Putin has threatened to use nuclear weapons, saying that Ukraine could be provoking them to take that step. The fighting itself could continue for weeks, months or even longer.
Dr Muraviev said he believes the prospect of the nuclear threat being engaged by Russia is low, with the threat more aimed at Western nations as a deterrent against any further intervention.
"I think the threat of nuclear weapons is more to deter the West from any aggressive moves or considerations of applying military pressure on other parts of Russia, in order to dilute Russia's resources away from the war in Ukraine," he said.
"And therefore, it also partially explains why Russia hasn't committed more military resources because it keeps a significant military contingent along its perimeter."
Professor Edele said there are too many uncertainties to know what will happen with the nuclear weapons threat, but said the Russian army has capacity constraints that will limit how long they can engage in a protracted war.
Civilians in Irpin, on the outskirts of Kyiv, evacuate in cars, driving past a destroyed Russian tank on 9 March 2022. Source: AP / AAP
Analyst Dr Malcolm Davis, from the Australian Strategic Policy Institute in Canberra, says he sees two ways the conflict would unfold: a coup against Mr Putin, or a further escalation in violence from the Russian army.
"I don't see an outcome in this conflict whereby suddenly Putin appears at the negotiating table ready to negotiate a ceasefire, it is more likely that this conflict will end one of two ways. Either Putin will be removed in a coup d'etat [coup] because he has failed, or he will escalate this conflict," he said.
"And there's already discussion now about the Russians trying to create a false flag operation [pinning the blame for military action on another party] for the use of chemical and radiological weapons in Ukraine. There's already been documented instances of the Russians using thermobaric and cluster munitions. So I think it's more likely that he will escalate this conflict rather than backing down."
US, NATO and others have opposed Ukraine's call for a no-fly zone. What further steps could Western nations take?
This satellite image shows a military convoy southeast of Invankiv, northwest of Kyiv in Ukraine on 28 February 2022. Credit: Maxar Technologies
There is a concern such an act could further antagonise Russia.
A former US ambassador to NATO and special representative for Ukraine, Kurt Volker, said a "limited" no-fly zone could help protect civilian populations and act as a centre for humanitarian aid efforts.
Dr Muraviev said there could be merit in a limited no-fly zone over western Ukraine where Mr Putin faces the toughest opposition from the Ukrainian population.
"The western part of Ukraine, historically, the western part of Ukraine was most anti-Russian. Since the Soviet annexation of it from Poland in 1959. The presence of ethnic Russian-Ukrainians there is minimal compared with the country's southern or eastern regions. So if if NATO will impose a no-fly zone over western Ukraine, it will then help preserve at least part of Ukraine under the control of its current government."
Mr Abramowicz said it is a difficult decision for Western nations.
"It's a really grim calculation that's going to be happening in the western capitals, and in Kyiv, and in Russia. No one wants to end up at war with Russia, if they can avoid it. You know, ultimately it is a nuclear-armed great power," he said.
"With the no-fly zone, you need armed units to enforce that. And that then would mean you would have NATO potentially directly shooting at Russia, which is a whole escalation no one wants.
"In terms of additional chess pieces, you know, I do think measures that are more likely include: potentially further expanding sanctions and expanding the type of arms provided."
That could even involve the US providing complex drones to Ukraine, he said.
"And maybe that's the sort of thing that you'd be Washington might look at if Moscow tries something brutal like flattening suburbs and using these long-range artillery pieces, because then if Moscow escalates to doing that, well, you know, you need to be able to increase the hurt as well," he said.
The United Nations said the number of refugees fleeing Ukraine has reached two million in what is the fastest-growing refugee crisis in Europe since World War Two.
