What’s the latest?
Planned civilian evacuations from two besieged Ukrainian cities have been called off, as Russian forces move closer to Odessa.
The Russian defense ministry said its units had opened humanitarian corridors near Mariupol and Volnovakha, a much smaller city 40 m miles (65km) to the north. But the Mariupol city council said Russia was not observing the ceasefire and asked residents to return to shelters and await further information on evacuation.
In the north of Ukraine, battles involving airstrikes and artillery are continuing north-west of Kyiv, and a vast Russian armored column remains outside the capital.
Guardian reporter Shaun Walker shared this footage from Bila Tserkva, 50 miles south of Kyiv.
Elsewhere, in the eastern city of Kharkiv, which is still coming under heavy fire, a blogger’s video message was interrupted by a missile exploding above him.
Ukraine released footage it said showed a Russian helicopter being downed.
The UN refugee agency said 1.3 million people have so far fled the fighting, and that the figure could rise to 1.5 million by the end of the weekend.
What has happened since Russia invaded?
On Thursday 24 February, Russia attacked Ukraine along multiple axes, bringing to a calamitous end weeks of fruitless diplomatic efforts by western leaders to avert war. Fighting and other military activity took place around and on the way to Kyiv. A substantial attack was aimed at the eastern city of Kharkiv. Russian forces also headed north and east from Crimea.
On Friday 25 February, Russian forces reached the outskirts of Kyiv and carried out an amphibious assault from the Sea of Azov near Mariupol. The shape of the Russian incursion became clearer:
On Saturday 26 February, Russian forces in control of territory to the north-west of Kyiv continued their assault on the capital. Elsewhere, heavy fighting was reported in and around Kharkiv and there were Ukrainian counterattacks in some places previously claimed by Russian forces.
On Monday 28 February, Russian rocket attacks killed dozens of people in Kharkiv. Pre-dawn blasts were heard again in Kyiv and in Mariupol, which was surrounded by Russian forces and under heavy attack.
On Tuesday 1 MarchRussian forces bombarded the government headquarters in Kharkiv, and the armored column continued rolling towards the capital.
On wednesday 2, Moscow’s forces took the port and train station in the strategically important city of Kherson, on the Black Sea. Russian paratroopers landed in Kharkiv overnight, after several days of fierce bombardment that killed or wounded dozens of civilians. Kyiv came under more heavy shelling as Russian forces stepped up their offensive and moved closer towards the capital in an apparent attempt to encircle it. Mariupol was reportedly surrounded by Russian troops.
A week into the Russian invasion, on Thursday 3 March, the Black Sea port of Kherson became the first major Ukrainian target to fall under the de facto control of Moscow’s forces. On friday 4the Zaporizhzhia nuclear plant was seized by Russian military forces after a fire sparked by overnight shelling burned for several hours at the largest facility of its kind in Europe.
How did we get here?
Over the past few months Russia deployed hundreds of tanks, self-propelled artillery and short-range ballistic missiles from as far away as Siberia to within striking range of Ukraine.
Moscow’s rhetoric grew more belligerent. Vladimir Putin demanded legal guarantees that Ukraine would never join Nato or host its missile strike systems, concessions he was unlikely to receive. A flurry of diplomatic activity did little to ease tensions.
The second half of February was long seen as the most likely period for a potential offensive. Russian soldiers stayed on in Belarus beyond the end of planned military exercises, and the Winter Olympics, hosted by Russia’s ally China, concluded.
The invasion was preceded on 22 February by Putin saying Russia would recognize the territorial claims of self-proclaimed republics in Luhansk and Donetsk. He had already ordered his forces into Russian-controlled territory in Ukraine.
What do we know about Russia’s deployments?
Scores of battalion tactical groups – the smallest operational unit in Moscow’s army, consisting of about 800-1,000 troops – were put in place near the borders of Ukraine in Russia and latterly Belarus prior to the invasion. As of 18 February, the US estimated that Russia had between 169,000 and 190,000 personnel in and around Ukraine.
An estimated 32,000 separatist forces were already operating in the breakaway areas in Donetsk and Luhansk – some of whom were likely to be unacknowledged Russian forces – before the invasion.
Many of the heavy weapons stationed near Ukraine arrived as far back as spring 2021. Over the new year Russia also began to move tanks, artillery, air-defence systems and fighter jets to Belarus for joint exercises in February. That deployment has since grown.
These satellite image composites show the buildup of troops in Yelnya and Pogonovo over the new year.
Satellite photographs also show increased deployments in Novoozernoye, in western Crimea.
The US estimates that 10,000 troops moved into Crimea in late January and early February.
Satellite images taken on 20 February showed troops and equipment being moved from holding areas to potential launch locations.
How do the militaries compare?
Russia’s invasion pits the Kremlin’s large, recently modernized military against an adversary largely using older versions of the same or similar equipment, dating back to the Soviet era. Russia has significant numerical advantages on land and in particular in the air and at sea, although Ukrainians are defending their homeland.
What is the historical context?
In 2014 Putin sent troops to annex Crimea, a mainly Russian-speaking region of Ukraine. Russia also incited a separatist uprising in Ukraine’s south-east, clandestinely sending soldiers and weapons to provoke a conflict that grew into a full-blown war.
A 2015 peace deal established a line of demarcation and called on both sides to make concessions. Since then low-level fighting has continued along the front, and each side has accused the other of violating the agreement.
Going back further, Russia has long opposed any attempts by Ukraine to move towards the EU and Nato. One of Putin’s often repeated demands is a guarantee that Ukraine never joins Nato, the alliance of 30 countries that has expanded eastwards since the end of the cold war.
What is the role of Nord Stream 2?
On 22 February, the German chancellor, Olaf Scholz, stopped the certification process for the Nord Stream 2 gas pipeline in response to Russia’s recognition of the two self-proclaimed republics.
First announced in 2015, the $11bn (£8.3bn) pipeline owned by Russia’s state-backed energy firm Gazprom was built to carry gas from western Siberia to Lubmin in Germany’s north-east, doubling the existing capacity of the Nord Stream 1 pipeline and keeping 26m German homes warm at an affordable price.
Nord Stream 2, Europe’s most divisive energy project, bypassed the traditional gas transit nation of Ukraine by running along the bed of the Baltic Sea. It faced resistance within the EU, and from the US as well as Ukraine, on the grounds that it increased Europe’s energy dependence on Russia, denied Ukraine transit fees and made it more vulnerable to Russian invasion.
George is Digismak’s reported cum editor with 13 years of experience in Journalism