What is happening?
Vladimir Putin has said Russia will recognise the territorial claims of its two proxy states in east Ukraine, and has ordered his forces into Russian-controlled territory, in a sharp escalation of already high tensions.
The move follows days of warnings by the US and others of the possibility of an imminent Russian invasion of Ukraine.
On 22 February a Reuters witness saw columns of military vehicles including tanks and APCs on the outskirts of Donetsk, the capital of one of the territories claimed by Russia:
How did we get here?
Over the past few months Russia has forward-deployed hundreds of tanks, self-propelled artillery and even short-range ballistic missiles from as far away as Siberia to within striking range of Ukraine.
Moscow’s rhetoric has also grown more belligerent. Putin has demanded legal guarantees that Ukraine will never join Nato or host its missile strike systems, concessions he is unlikely to receive. A flurry of diplomatic activity has done little to ease tensions.
The second half of February was long seen as the most likely period for a potential offensive. Russian soldiers have stayed on in Belarus beyond the end of planned military exercises, and the Winter Olympics, hosted by ally China, have concluded.
What do we know about the deployments?
Scores of battalion tactical groups, the smallest operational unit in Moscow’s army consisting of around 800-1,000 troops, have been put in place near the borders of Ukraine in both Russia and latterly Belarus. 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 of Donetsk and Luhansk – some of whom were likely to be unacknowledged Russian forces – before Putin’s announcement that he was sending in troops.
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.
Nato has warned that Russian forces in Belarus could reach 30,000, including Speznaz special operations forces, SU-35 fighter jets, S-400 air defence systems and Iskander missiles, which can carry nuclear weapons, and have a range of 500km.
Half of Russia’s air force is now deployed near Ukraine, according to western estimates, and Russian warships have been conducting training exercises in the Black Sea. This footage released by the Russian MOD shows a Ka-27PS helicopter taking off and landing on the deck of a frigate during exercises on 22 February:
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 10,000 troops moved into Crimea in late January and early February. This image from 18 February shows deployments including armour, helicopters and field hospitals in Novoozernoye:
Satellite images taken on 20 February showed troops and equipment being moved from holding areas to what the UK defence secretary described as potential launch locations.
What may happen next?
Putin’s decision to formally recognise the territorial claims of the self-proclaimed republics of Donetsk and Luhansk allows him to justify a further invasion of Ukraine beyond the existing of line of contact. This in turn could be the prelude to a broader conflict.
A further invasion could take place on multiple axes, with Russian forces trying to encircle Ukraine’s military in the east of the country, though western intelligence agencies believe the most likely goal of a Russian offensive would be to surround Kyiv and force regime change.
Belarus is considered the simplest invasion route to Ukraine’s capital as it would allow Russian forces to cross the large Dniepr river in friendly territory and attack from the west.
This runs counter to the thinking in Ukraine as of late January that a focused attack in the east was the most likely scenario. On 21 January Ukrainian military intelligence said that since the beginning of the month Moscow had supplied separatists in eastern Ukraine with additional tanks, self-propelled artillery, mortars and more than 7,000 tons of fuel.
A map released by Ukrainian military intelligence in November showed a worst-case scenario: Russian forces crossing the Ukrainian border from the east and attacking from annexed Crimea, as well as launching an amphibious assault on Odessa with support from Russian soldiers in Transnistria and troops sent in from Belarus.
How do the militaries compare?
Any invasion by Russia into Ukraine will pit the Kremlin’s large, recently modernised 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 air and at sea, although the Ukrainians would be 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 both sides have 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 giant Gazprom has been 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.
Europe’s most divisive energy project, Nord Stream 2 bypasses the traditional gas transit nation of Ukraine by running along the bed of the Baltic Sea. It has faced resistance within the European Union, and from the United States as well as Ukraine, on the grounds that it increases Europe’s energy dependence on Russia, denies Ukraine transit fees and makes it more vulnerable to Russian invasion.