What’s the latest?
The Russian invasion of Ukraine continues, with forces from Moscow having taken the port and railway station of the strategically important city of Kherson on the Black Sea. Russian paratroopers landed at 3 a.m. Wednesday in Ukraine’s second-largest city, Kharkiv, security chiefs said, after days of heavy shelling that killed or injured dozens of civilians. Kiev has also come under more intense shelling as Russian forces step up their offensive and close in on the capital in an apparent attempt to encircle it. Mariupol, a strategically important port city on the Sea of Azov, would be surrounded by Russian troops.
Armored vehicles and Russian soldiers patrolled Kherson.
A video released by Ukraine’s Emergencies Ministry shows firefighters trying to put out a fire at the Interior Ministry’s regional headquarters in Kharkiv.
Video footage shows destroyed windowless residential buildings, fallen trees and power lines, following strikes that killed at least 11 people in Kharkiv.
What has happened since the Russian invasion?
Last Thursday, Russia attacked Ukraine from multiple axes, bringing a calamitous end to weeks of failed diplomatic efforts by Western leaders to avert war.
Fighting and other military activity took place around and on the way to Kyiv.
A major attack targeted the eastern city of Kharkiv.
Russian forces also moved north and east from Crimea.
On Friday, Russian forces reached the outskirts of Kiev and conducted an amphibious assault from the Sea of Azov near Mariupol. The shape of the Russian incursion became clearer.
On Saturday, Russian forces controlling territory northwest of Kiev 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, Russian rocket attacks killed dozens of people in Kharkiv.
Predawn explosions were again heard in Kyiv and Mariupol, which was surrounded by Russian forces and under heavy attack.
On Tuesday, Russian forces shelled the seat of government in Kharkiv, and the armored column continued to roll towards the capital.
How did we come here?
Over the past few months, Russia has 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 has become more belligerent. Vladimir Putin demanded legal guarantees that Ukraine would never join NATO or host its missile strike systems, concessions he was unlikely to obtain. A flurry of diplomatic activity did little to ease tensions.
The second half of February has long been considered the most likely period for a potential offensive. Russian soldiers have remained in Belarus beyond the end of scheduled military exercises, and the Winter Olympics, hosted by Russia’s ally China, have come to an end.
The invasion was preceded on February 22 by Putin declaring that Russia would recognize the territorial claims of the self-declared republics in Luhansk and Donetsk. He had already ordered his forces to enter Russian-held territory in Ukraine.
What do we know about Russian deployments?
Dozens of battalion tactical groups – the Moscow Army’s smallest operational unit, consisting of around 800-1,000 soldiers – were set up near Ukraine’s borders in Russia and later in Belarus before the invasion. As of February 18, the United States estimated that Russia had between 169,000 and 190,000 troops in and around Ukraine.
An estimated 32,000 separatist forces were already operating in the separatist areas of Donetsk and Lugansk – some of which were likely unrecognized Russian forces – before the invasion.
Many heavy weapons stationed near Ukraine arrived as early as spring 2021. In the new year, Russia also began moving tanks, artillery, air defense systems and combat aircraft to Belarus for joint exercises in February. This deployment has since increased.
These satellite image composites show the buildup of troops in Yelnia and Pogonovo over the new year.
Satellite photographs also show increased deployments in Novoozernoye, western Crimea.
US estimates 10,000 troops entered Crimea late January and early February.
Satellite images taken on February 20 showed troops and equipment being moved from holding areas to potential launch locations.
How do the military compare?
The invasion of Russia pits the large, newly modernized Kremlin army against an adversary largely using older versions of the same or similar gear, dating back to the Soviet era. Russia has significant numerical advantages on land and especially in the air and at sea, even if the Ukrainians are defending their homeland.
What is the historical context?
In 2014, Putin sent troops to annex Crimea, a predominantly Russian-speaking region of Ukraine. Russia also instigated a separatist uprising in southeastern Ukraine, smuggling in soldiers and weapons to provoke a conflict that turned into a full-blown war.
A 2015 peace accord drew a dividing line and called on both sides to make concessions. Since then, low-intensity 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 attempt by Ukraine to draw closer to the EU and NATO. One of Putin’s oft-repeated demands is a guarantee that Ukraine will never join NATO, the 30-nation alliance that has expanded eastward since the end of the Cold War.
What is the role of Nord Stream 2?
On February 22, German Chancellor Olaf Scholz halted the certification process for the Nord Stream 2 gas pipeline in response to Russia’s recognition of the two self-declared republics.
First announced in 2015, the $11bn (£8.3bn) pipeline owned by Russian state-backed energy company Gazprom was built to transport gas from Western Siberia to Lubmin in northeast Germany, doubling the existing capacity of the Nord Stream 1 gas pipeline and keeping 26m of German homes warm at an affordable price.
Europe’s most controversial energy project, the Nord Stream 2 route bypasses the traditional gas transit nation of Ukraine along the bed of the Baltic Sea. He has faced resistance in the EU, the US and Ukraine, on the grounds that he is increasing Europe’s energy dependence on Russia, denies charges transit to Ukraine and makes it more vulnerable to Russian invasion.