A full invasion of Ukraine, with the aim of pacifying the capital, Kyiv, would result in Vladimir Putin starting a war on a scale not seen since Iraq in 2003 – prompting western experts to question whether a lasting Russian victory could be achieved.
Estimates suggest about 100,000 Russian troops are massing near Ukraine’s borders. Yet, experts following the crisis closely say that for an invasion of the whole country that number would need to nearly double again, and would almost certainly involve forces passing through Belarus.
Dr Fred Kagan, a senior fellow at the American Enterprise Institute, said: “This will likely require an invasion on a scale not dissimilar to 2003, somewhere between 150,000 and 200,000 troops.”
He predicted that a force that size could be in position by the end of January. About 175,000 US and other allied troops were involved in the invasion of Iraq.
Is occupation possible?
Kagan, who co-authored a series of reports that led to the 2007 US troop surge in Iraq, said the real challenge for Putin was how an almost certainly hostile Ukraine may be held by the Russians if there was an insurgency after the capture of Kyiv.
A determined operation would require one counter-insurgent per 20 inhabitants, said Kagan in a paper he co-wrote with other experts from the Institute for the Study of War. That “would suggest a counter-insurgency force requirement on the order of 325,000 personnel” would be needed to hold Kyiv and Ukraine’s major cities in the south and east, they added.
Ukraine has an army of 145,000, according to the International Institute of Strategic Studies (IISS),, but there are also an estimated 300,000 veterans of the low-intensity conflict in the Donbas region of the country that started in 2014. Polling says a third of Ukraine’s citizens would be willing to take up “armed resistance”.
Burnt by the Soviet experience in Afghanistan, Russia generally viewed US attempts to hold countries against insurgents as a mistake. “Putin will have studied what happened to the US in Iraq after 2003. The difficulties of dealing with partisan activity keeps my mind open to the possibility that the Russian president does not intend to invade and conquer Ukraine,” Kagan told the Guardian.
Nevertheless, Moscow has overwhelming advantages in terms of an initial invasion, most notably in terms of rocketry and airpower. Ukraine faces potentially terrifying consequences, in an all-out assault, which could shatter a country’s morale and prompt millions to flee west, rather than fight.
Rob Lee, a former US marine and fellow with the Foreign Policy Research Institute, said: “Russia has the capacity to devastate Ukraine’s military units from afar with weapons such as Iskander ballistic missiles. We almost never see modern weaponry like this unleashed; it gives Russia the capability to inflict thousands of casualties a day.”
A military assault will also have a transformational effect on international opinion. Civilian casualties in considerable numbers are almost certain, amounting to an operation unlike almost any Putin has conducted before, including the war with Ukraine in 2014, where responsibility for military action was denied.
Dr Samir Puri, a senior fellow at the IISS, who has previously spent a year as a conflict monitor in Ukraine, said: “It is hard to imagine a full invasion without the use of airpower, but that is such a huge threshold for Russia to cross.”
Much has been made about Ukraine’s recent purchase of weapons from the west, but the Javelin antitank missiles have a range of about 1.5 miles (2.5km) and can only delay an mechanised advance.
The country has a relatively modest number of Turkish TB2 drones for now, half a dozen or a dozen, tiny compared with Russia’s thousands of tanks, the core of any ground force.
Russia also has to decide how to deal with Ukraine’s cities, principally Kyiv, with a population of 3 million, but also Kharkiv in the north-east, with a population of almost 1.5 million. “Urban warfare is hard, it does fearful damage and Russia struggled with it in Aleppo,” Kagan said, citing Putin’s intervention in Syria’s civil war.
Speculation about Russia’s plans – based in part on apparent leaks published in the German newspaper Bild – suggests the Kremlin would surround Kharkiv and ultimately Kyiv, cutting off supplies, hoping in a medieval fashion they will surrender. That may be less violent but would still undercut the idea of Russia acting as a unifying force.
Nor is encircling Kyiv easy, western analysts say. The key points of the city, including the presidential palace, are to the west of the readily defensible Dneiper River. The first bridges south of the city are 60 miles away; a dam four miles north has turned the stretch of the river that runs to the border with Belarus into a lake.
The simplest way across the river is to cross in a safe territory – Belarus to the north. That would require Minsk’s support, which would be highly probable given its recent rapprochement with Moscow. In a speech to mark Orthodox Christmas on 7 January, the Belarusian president, Alexander Lukashenko, said his country would “do everything” to take back Ukraine.
Russian mechanised forces would aim to encircle Kyiv from the west. One route is to cross the Pripet marshes, which freeze in winter, and the Chernobyl area (not deemed a great complication for a modern military able to operate in a radiation zone).
An alternative would be to strike from further west in Belarus, such as the Baranovichy training area. A key sign that Russia is ready to act, Kagan said, will be if “Russian mechanised forces deploy to Belarus”.
Even if Putin does not invade, a permanent Russian military garrison in Belarus would have advantages to the Kremlin, as an potential threat not just to Ukraine but to the Baltic states to the north. It would “create a large military base that would give Russia air dominance over Nato’s eastern flank”, said Orysia Lutsevych, a research fellow at foreign policy thinktank Chatham House.
Putin’s military alternatives
The risks inherent in invasion and occupation leave experts such as Dr Taras Kuzio, an associate fellow with the Henry Jackson Society,arguing in a newly released paper that an all-out attack “the least likely” of the military scenarios available to Putin. Instead, the Ukraine expert sees three other options.
In the first, Russia simply occupies and annexes the part of the Donbas controlled by separatists, a partial invasion mirroring the 2008 Georgia crisis. That began, Kuzio wrote, after “repeated military provocations” by proxies “led to intervention by Georgian troops”, giving Putin a pretext to respond.
A second is to enlarge the occupied territory with a land corridor to previously annexed Crimea, capturing the coastal city of Mariupol. Russia could also seize other key industrial sites and try to degrade Ukraine’s nearby military. “They could take out Turkish TB2 drones and artillery in the Donbas” in an overt, limited campaign designed to weaken Ukraine, said Lee.
A final option, said Kuzio, is the “revival of the 2014 ‘New Russia’ project” that would try “to cut Ukraine off from the Black Sea”. This would amount to seizing the south, capturing the port of Odessa and perhaps the industrial city of Dnipro.
Taking Odessa, population 1 million, would probably require a dramatic air and naval operation, using paratroopers from Crimea followed by marines landing on nearby beaches.
Of those options, annexing occupied Donbas would almost certainly be popular in Russia, However, it would be an extremely limited response given the Kremlin’s insistence that its chief goal, as most recently repeated by Sergei Ryabkov, Russia’s deputy foreign minister, is “the non-expansion of Nato, the non-accession of Ukraine, Georgia and other countries to the alliance” – raising concerns that a military campaign is probable.
“You have to take a step back and ask what Russia’s political goals are,” said Lee. “If Russia wants to force a change in Ukraine’s political orientation, you can see why the Kremlin might look at military options.”