The dugouts of the Donbas region, sometimes fortified with little more than sandbagged gun emplacements and makeshift wooden planks, are seen by their defenders as a bulwark against Russian aggression on the continent. They consider they are not just protecting Ukraine, but Europe as a whole.

The Ukrainian separatists will tell you they are stopping the spread of a NATO alliance that threatens to engulf Russia, and leave it defenceless.

Troops on both sides have been facing each other down across this line of contact since a ceasefire ended large-scale combat in 2015 – although deadly warfare has continued ever since. But in recent months, Europe’s most dangerous conflict has threatened to re-emerge, throwing the future of millions of Ukrainians into grave doubt.

New Russian troop concentrations on Ukraine’s border have sparked fears of an invasion. They are backing up Russia’s attempt to negotiate a new sphere of influence in Ukraine by demanding the US guarantee that Ukraine will never join NATO – a demand the US has rejected – and for progress on the stalemate over Donbas.

Relations between Russia and Ukraine – and indeed the US and Europe – have been tense since 2014. In that year, Russia not only annexed Crimea, which is Ukrainian territory, but also supported a separatist movement in Donbas – an area that includes Donetsk and Luhansk, Ukraine’s two easternmost regions, which share a border with Russia.

Fourteen thousand people have died as a result of Russia’s war on Ukraine, which emerged in the aftermath of the country’s Euromaidan Revolution in 2013. Two million people from Donbas have been displaced, fleeing to Ukraine and Russia. Yet thousands of Ukrainian citizens continue to cross the line of contact between the uncontrolled Donbas territories and Ukraine proper every day.

To understand the ins and outs of the situation, read on.

What do I need to know?

The current situation comes after eight years of war in Ukraine, and with, apart from Vladimir Putin, a new set of leaders on all sides.

Since war broke out in 2014, the two separatist territories in Donbas – which are not officially recognised by any national government, including Russia’s – have become more fully integrated into Russian control. A series of mysterious arrests, deaths and disappearances of self-declared public officials and field commanders in the territories has been followed by the appointment of figures with closer ties to Moscow.

Though Moscow has increased control, the territories remain a grey zone for civil and workers’ rights, as well as opaque and criminal business. More than 700,000 Russian passports have now been issued to residents of the territories, which Ukraine’s President Volodymyr Zelenskyy has called a “sign of annexation”.

In Russia itself, public opinion appeared firmly on Putin’s side in the aftermath of the annexation of Crimea. But as the Russian president enters his 23rd year in office, there are signs of a legitimacy crisis in the country – which may have prompted the current escalation.

There is, so far, little discussion of possible war from the Russian opposition, which has been decimated by repression.

In Ukraine, President Volodymyr Zelenskyy came to power in 2019 on a campaign that promised peace. Relations between his predecessor Petro Poroshenko and Putin were respectful, though Poroshenko steered a tough campaign against Russia. Zelenskyy, on the other hand, is not believed to have the same level of authority with the Kremlin, and has made a series of moves against Russian interests in the country. These have included sanctions on pro-Russian TV channels and a criminal investigation into Viktor Medvedchuk, an oligarch close to Putin. Today, the country holds tighter political, economic and security relationships with the US, UK and EU states.

Could sanctions deter Russia?

With some NATO member states signalling they won’t send troops to support Ukraine in the face of a Russian invasion, one of the last arrows in the quiver of those looking to deter the Kremlin is the threat of economic isolation. Sanctions that have been proposed include removing Russia from the SWIFT banking sector and banning imports of Russian oil and gas. After the annexation of Crimea, the Russian economy was hit with a range of targeted, but limited sanctions on key industries.

George Voloshin, an expert on the economy of Russia and other post-Soviet states, warns that there are no sanctions left to put on Russia that would not also have serious blowback on Western countries. “Going further with sanctions would be painful for everyone involved. We’re at a stage where you’ve used all the small arms in your economic arsenal – now you need to use a bazooka.

“These tools will have dramatic consequences not just in Russia, but in Europe as well. Russia is the second-largest oil and gas producer in the world – this isn’t like losing oil barrels from Venezuela, which has a negligible impact on the global economy."

In addition, Russia has been making ‘rainy day’ preparations for its economy to withstand more sanctions, including developing a domestic equivalent to SWIFT banking. Public opinion polling shows that ordinary Russians are much less concerned by the threat of economic isolation than they were in 2014. While Russia’s economy has suffered lacklustre growth since then due to Western sanctions, there are few signs that this has affected the Putin regime’s domestic stability.

Another option would be for European stakeholders to cancel the Nord Stream 2 pipeline project, which would carry gas under the Baltic Sea directly from Russia to Germany, bypassing Ukraine. This pipeline dramatically lowers Kyiv’s leverage in any dispute.

The US has opposed Nord Stream 2 from the beginning, with secretary of state Antony Blinken recently calling it a “Russian geopolitical project that threatens European energy security and undermines the security of Ukraine”. But so far Germany, Russia’s main partner in the project, has given little indication that it would be willing to cancel – until signs from the German foreign minister on Thursday.

In the UK, the escalation has come at a time of increased interest in the concentration of oligarch and suspect wealth in London. Transparency International has identified $1.5bn worth of property belonging to Russian oligarchs and organised crime, and British MPs have called for greater transparency over these assets.

What diplomatic efforts are being made?

There are several diplomatic channels. The first is the Trilateral Contact Group, which includes representatives of Ukraine, Russia and the Organization for Cooperation and Security in Europe (OSCE). The group first met in June 2014, and signed an agreement in Minsk, Belarus, later that year.

It didn’t, however, stop heavy fighting resuming the following winter, when pro-Russian and Russian forces took a series of key positions in Donbas, brutally pushing Ukrainian troops back.

The Trilateral Contact Group met again in Minsk and signed a new agreement known as Minsk 2. This agreement set out a plan for ceasefire and later reintegration of the occupied Donetsk and Luhansk territories via elections, a special status in Ukraine’s constitution and an amnesty for those who had participated in the armed uprising.

The second principal channel is the Normandy Format, comprising Ukraine, Russia, France and Germany. This is a series of talks linked to the Minsk agreements. There are also the NATO-Russia Council and the OSCE talks with Russia.

What is the problem with the Minsk 2 agreement?

Minsk 2 is the focus of discussions over the separatist Donbas region of Ukraine today. Ukrainian officials have previously called the document a political and diplomatic gesture which is not binding under international law; Russia considers it binding.

The Ukrainian authorities are reluctant to recognise any special status for the territories outside of its control, as it would give Russia leverage over Ukrainian territory. Previously, public protests have broken out in Ukraine over concerns of capitulation to Russia.

More practically, Minsk 2 foresees that as part of the reintegration of the uncontrolled territories in Donbas, local elections will be held. The Ukrainian government states that elections can take place only after it resumes control over its border and territory in eastern Ukraine. Russia’s interpretation, in contrast, focuses on the order of the steps as laid out in the agreement.

What is the military balance between Russia and Ukraine?

In December commercial satellite images showed several unusual Russian troop deployments in strategic locations near Ukraine’s borders. One series was a base in Crimea that had been near disuse in October, but by December was bristling with Russian armour and personnel.

Other photos published since then show military build-ups on northern border regions and – most concerningly – deployments on the Belarusian border within striking distance of Kyiv.

In addition to the approximately 127,000 troops now stationed near the Ukrainian frontier, the Russians have also deployed artillery, armoured vehicles and air defences. Ukrainian intelligence has also reported evidence of increased flows of aid and military equipment and supplies to the Donbas separatist forces.

After the breakup of the Soviet Union, Ukraine was left with one of Europe’s largest armed forces. But by the outbreak of hostilities in 2014, Ukraine’s military had been hollowed out due to decades of corruption and underinvestment.

Ukraine’s senior military staff still privately grumble that they were given advice by their Western military advisers not to contest Putin’s annexation of Crimea, a decision that many remain bitter over.

When Ukrainian forces attempted to retake major separatist-held territories in early 2015, they were encircled and suffered a rout at the Battle of Debaltseve. It was this defeat that forced Ukraine to start negotiations and temporarily abandon ambitions to regain control of its territory through military means.

The bitter fighting also killed civilians – whether in the rocket attacks on Mariupol by separatist forces in January 2015 or in the airstrike on government buildings in Luhansk by Ukrainian forces in mid-2014. Civilians remain at high risk today, as thousands continue to cross the line of contact and live in the surrounding areas.

Since the start of the war, a programme of radical reforms, Western military training and a significant increase in military funding has left Ukraine with modern, well-equipped armed forces numbering over 200,000 service people. They could put up serious resistance to a further Russian invasion.

The Ukrainian army has also been bolstered by Western military aid. In 2018, the Trump administration began providing hand-held Javelin anti-tank missiles to Ukrainian forces. More recently, they received Turkish Bayraktar TB-2 drones, the same uncrewed aircraft that gave Azerbaijani forces a decisive advantage in that country’s 2020 war with Armenia over Nagorno-Karabakh.

Yet the issue of foreign aid has also caused divisions in Western capitals. While Washington and London pledged to increase offensive military aid, Berlin has been much more sceptical, even blocking the transfer of German-made weapons from the Baltic states to Ukraine.

Where would a Russian attack come?

Depending on how much of a gamble Moscow decides to take, Russia has several military options. At one end, there is a ramping-up of existing ‘hybrid warfare’ measures including cyber-attacks, industrial sabotage and increasing military aid to the Donbas separatists. The other extreme is a full-scale invasion and occupation that attempts to install a pro-Kremlin government in Kyiv by force.

If the Russians were to launch an invasion, there are broadly three possible routes, according to the Center for Strategic and International Studies. Russian forces could move through the separatist republics and Ukraine’s north-east up to the Dnipro River, which would probably involve attempting to besiege Kharkiv, Ukraine’s second-largest city.

Russian troops could also break north from their existing bases in occupied Crimea and attempt to capture Black Sea ports such as Mariupol, Kherson and most crucially, Odessa. This would cut Ukraine off from the sea and threaten its economic viability as a state.

The most daring option would be an attack from Belarus in a decapitation strike that quickly captures Kyiv and topples the Ukrainian government.

Weather conditions will determine what Russia can do. The current winter weather and frozen ground makes an armoured assault possible, but by March the thaw will make large parts of eastern Ukraine swampland, neutralising Russia’s armour advantage and favouring the defenders. Russia would have to wait until summer, allowing Ukraine crucial time to prepare and reinforce, as well as corral international opinion on its side.

Ukrainian military observers are increasingly convinced that Russia will limit itself to a targeted escalation in the existing eastern battlegrounds rather than risk full-scale war.

A widely circulated report by the Center for Defense Strategies, a leading Ukrainian think tank, said that an offensive designed at capturing Ukraine is unlikely based on current troop movements. They estimated that around 66 battalions’ worth of strength is amassed on the borders, but that Russia would need perhaps double this to overwhelm Ukraine. It would take around three weeks to prepare a force of that size, suggesting that a large-scale attack is not imminent. Russian troops have also not been organised into the battalion groups that would be used in a war.

A senior Ukrainian defence official, who spoke with openDemocracy on condition of anonymity, concurred with this analysis, saying: “We are not seeing the signs that would accompany massive military operations. The concentration of forces on the border is simply not sufficient to break our lines. Of more immediate concern would be an escalation of the existing conflict in already occupied territories.”

That official gave the example of Mariupol, a Ukrainian port city on the Sea of Azov which has been the site of several assaults since the conflict began. “We see a breakout operation as a real possibility. Mariupol is one of the sites in our chain of defences that is causing us real concern.”

Others, however, have suggested that Russia is bluffing in order to gain a diplomatic advantage.

What is the US saying?

While the US argues that Russia is not upholding its commitments under the Minsk 2 agreement – and says that it is ‘actively violating’ them – it suggests that Ukraine must go ahead with it.

“I don’t think there’s any need to renegotiate [Minsk 2],” said US secretary of state Antony Blinken recently. “If Russia is serious about Minsk, we are prepared to support that.”

As to NATO membership, on 26 January the US ambassador to Russia delivered two letters from the US and NATO, in which it is believed that the US reaffirmed Ukraine’s sovereignty and right to join NATO in the future. Blinken called the letter a “serious diplomatic path forward”, but noted it did not contain “explicit proposals”.

The US secretary of defence, Lloyd Austin, stated he was discussing the possibility of deploying US troops to eastern Europe together with NATO allies, and that 8,500 troops were on high alert. A packet of sanctions from the US is under preparation in case of Russian military escalation.

What about the UK?

The Russia-Ukraine crisis has come at a time of dwindling ratings for Boris Johnson, who has sought to help lead the West’s response to the situation, including with plans for sanctions on Russia.

“The British army leads the NATO battle group in Estonia and, if Russia invades Ukraine, we would look to contribute to any new NATO deployments to protect our allies in Europe,” Johnson said on 26 January.

Last weekend, the British Foreign, Commonwealth and Development Office said that it had evidence of a plan to install a pro-Russian leader in Ukraine, with Ukrainian politician Evgeny Muraev “a potential candidate” – a claim he laughed off, according to The Observer). The evidence was not released, and foreign-policy experts, including some in Ukraine, treated the announcement with scepticism.

In 2020, the UK signed a ‘strategic partnership’ agreement with Ukraine, which includes £1.7bn worth of financing for export credits related to the Ukrainian navy.

Alongside Russia and the US, the UK was a signatory to the 1994 Budapest Memorandum, in which Ukraine relinquished its nuclear arsenal in exchange for security and political guarantees.

What is Europe doing?

Germany and France are the key European partners in the Normandy Format. However, it is clear that Germany has lost the leadership it exercised in 2014, the last time tensions between Russia and the West were so high. Partially this is associated with the results of last year’s election, which brought the Social Democrats (SPD) to power. Social Democrats have a difficult and ambivalent relationship to Russia, trying to maintain the so-called ‘Ostpolitik’, a historical policy dating back to the 1970s that some say helped to defuse tensions in the Cold War and contributed to the eventual fall of the Soviet Union.

At the same time, the SPD understands that the current Russian regime is not reliable and that its last chancellor, Gerhard Schröder, betrayed European and German strategic interests by siding so closely with Putin and Gazprom, the Russian state-owned gas company.

In any case, the new chancellor, Olaf Scholz, is still finding his footing, while being overtaken by the more Russia-hawkish Green party in the governing coalition.

Several observers have surmised that Putin has also upped the ante now rather than in spring last year because Angela Merkel stepped down, leaving Germany in a relatively weak spot.

French President Emmanuel Macron, in contrast, is keen to claim the mantle of leadership and speak in the name of Europe, as illustrated in his direct call to Putin today. This has, in the past, ruffled feathers among other EU member states, particularly among central and eastern European states.

But there are also further, internal divides among European countries, such as between the current Hungarian government, probably the staunchest supporter of Russia in Europe, and the Baltic states, which are at the most critical end. Further differences of interests exist between southern (especially Italy) and northern (Finland and Sweden) states.

Nonetheless, the EU has passed unanimous sanctions against Russia in the past and now the overall message is that much more incisive sanctions are on the table if Russia attacks Ukraine.

Europe and the EU cannot act alone on Russia, but the transatlantic coordination on these issues, including in the G7, is close. The EU may appear soft and slow, but eventually it may pass severe and hurtful sanctions that give more long-term credibility to the actions of NATO and the US.

Finally, the EU is moving on other legal and structural fronts, such as the regulation of energy markets, the ‘European Green Deal’ and other legal instruments to restrict investments or sensitive investments. These are unlikely to impact the current stand-off, but should influence the Russian calculus.

What is Ukraine saying?

Ahead of a new Normandy Format meeting in Paris on 26 January, the Ukrainian authorities made a series of moves that appear to lay the groundwork for further talks on Donbas and introduce a note of calm.

“The risks have not just existed for a day, and they have not become bigger. The only thing that has become bigger is the hype around them,” said President Volodymyr Zelenskyy on 19 January.

That same day, the head of Ukraine’s National Security and Defence Council Oleksandr Danilov claimed in an interview that the West’s rising interest in the conflict was linked to their ‘own internal [political] processes’.

On 24 January, the Ukrainian government withdrew its draft law that would have legally identified Russia as an aggressor state. At the same time, Zelenskyy suggested in an interview to The Washington Post that if there was a large-scale invasion, Russia might invade Kharkiv, an eastern Ukrainian city with a population of over a million people.

Andriy Yermak, head of the Office of the President of Ukraine, called the resumption of the Normandy Format talks a “powerful signal”. Following the Paris meeting, Yermak called the talks “a positive signal”.

“The goal is to end the war, return our territories. And today the goal is also a de-escalation around Ukraine’s borders,” he said. During the proceedings, there were reports of pressure on Ukraine to agree to direct negotiations with authorities in the unrecognised territories.

The Normandy Format talks are set to resume in two weeks’ time in Berlin.

What is Russia saying?

In Russia there have been signs of further escalation.

In December, the Russian Foreign Ministry published a draft agreement between Russia and NATO member states that foreclosed the possibility of Ukraine and any other of Russia’s neighbouring states joining NATO. That draft also proposed no further military personnel or weapons being stationed in Europe. Not surprisingly, NATO has rejected the suggestions.

This month the head of United Russia, the ruling political party, stated that Russia should send “certain types of arms” to the separatist regions of Donetsk and Luhansk in Donbas, Ukraine, just as the Normandy Format talks were about to begin in Paris. This, he said, was in order to “prevent the military aggression that is clearly prepared by the Kyiv regime.”

In response, the head of the ‘Donetsk People’s Republic’, Denis Pushilin, called on Russia to send arms.

On 19 January, Russian parliamentarians put forward a proposal to officially recognise the ‘governments’ in the territories outside of Ukrainian control. This will be addressed by the Russian parliament in February.

The Russian government appears to be preparing to argue that a conflict, if it happens, was started by Ukraine and its Western allies. For instance, Russian defence minister Sergey Shoigu claimed that US mercenaries were planning a chemical warfare attack in Donbas in late December.

This theme of an alleged provocation from the Ukrainian side was recently taken up by Fyodor Lukyanov, chairman of the Council on Foreign and Defense Policy, a Russian government-aligned think tank, in an interview on Russian state TV. However, he said he did not believe there would be a large-scale conflict – and that a diplomatic understanding would eventually be reached as part of the ‘re-examination’ of the post-Cold War ‘system of security’.

Russian government speakers regularly question the legitimacy of the Ukrainian authorities, referring to them as the “Kyiv regime”. In an article earlier this year, in which Putin claimed that Russians and Ukrainians were “one people”, the Russian president essentially stated that the Kremlin was looking to restore control over Ukraine.

Following the 26 January meeting in Paris, Russian deputy prime minister Dmitry Kozak said there was “practically zero progress” after the eight-hour talks.

Putin has not made a public statement regarding Ukraine or the US since late December. According to Lavrov, after a Russian ministerial response is drawn up to the recent US and NATO letters to Russia, Putin will make a decision “on our next steps”. In those letters, it is believed the US made no commitments on the issue of future NATO membership for east European states.

Russia does not officially consider itself a party to the conflict in Donbas. Evidence points directly to the contrary.