The deployment of tens of thousands of Russian troops to Ukraine’s north, east, and south is fanning worries in Kyiv and Western capitals that Moscow is plotting a fresh invasion. Russia strongly rejects any such ambitions.
According to Western military analysts, Russia cannot retain such forces posted continuously for budgetary and logistical reasons, and will need to withdraw them by the summer.
Estimates of the number of fresh Russian troops sent closer to Ukraine range from 60,000 to 100,000, with a US intelligence dossier indicating the number might be increased to 175,000.
U.S. officials have said Russia might attack Ukraine as early as this month when the ground will be harder, making it easier for tanks and other armour to move swiftly.
At talks this week with the United States and NATO, Russia has sought security guarantees to defuse the crisis.
Foreign Minister Sergei Lavrov said on Friday Moscow was not ready to wait forever for a response and that it wanted a detailed written response to every Russian proposal.
But what might a Russian attack look like and what could it seek to achieve?
“The current deployments are versatile. They keep Russia’s options open and therefore keep the defender guessing,” said Keir Giles, an Associate Fellow at Chatham House.
Here are some possible scenarios.
Heavily armed Russian-backed separatists have controlled a swath of eastern Ukraine since 2014 and continue to exchange fire with Ukrainian government forces despite a 2015 ceasefire that ended major hostilities.
The conflict in Donbass has killed 15,000 people, Kyiv says. Ukraine has long accused Russia of having regular troops in the region, something Moscow denies.
Russia has accused Kyiv of harbouring plans to retake the region by force, something Ukraine denies.
In such a febrile atmosphere, the risk of a misunderstanding or unplanned escalation is greater, and Russia could use such an incident as a casus belli.
A source familiar with the Russian Defence Ministry’s thinking said this was the most likely scenario if Moscow decided to attack, but that he was unaware of any such decision. Kyiv might also be provoked into attacking by the separatists who could then ask Russia to send troops to help, he said.
Russian forces could expand the fighting in Donbass to draw Ukraine into a conventional conflict, said Neil Melvin, director of International Security Studies at the RUSI think-tank in London. He said Moscow could try to seize Ukrainian coastal areas on the Sea of Azov, creating a land bridge from the Russian city of Rostov through Donbass to Crimea, adding: “That would put the Ukrainian government under a lot of pressure.”
ASSAULT FROM CRIMEA
Russia has brought in new forces to Crimea, which it annexed from Ukraine in 2014.
Moscow could launch an attack on Ukraine from Crimea and seize territory up to the Dnieper River that could serve as a natural barrier against any Ukrainian counter-offensive, said Konrad Muzyka, director of the Poland-based Rochan consultancy.
The operation could begin with artillery, missile and air strikes on Ukrainian units in the south, and special forces units might seize bridges and railway junctions, allowing troops and tanks to advance, he said. There are only two roads from Crimea that could be blocked or destroyed, a potential weakness, he said.
Forces would secure control of a canal that provided Crimea with fresh water supplies until Russia annexed the region and Ukraine stopped the flow, he said.