Russia could be ready to launch fresh attacks on NATO's eastern flank as early as 2027 if a ceasefire in Ukraine is agreed this year, a security think tank has claimed.

The International Institute for Strategic Studies (IISS) said that Vladimir Putin's commitment to forcing Russia's economy and industry onto a war footing means that Moscow could reconstitute its forces for a fresh conflict within two years.

The report acted on the assumption that a ceasefire would be agreed in Ukraine later this year and that the US under Donald Trump could withdraw from NATO, or reduce American military presence on the continent to refocus on the perceived threat from China.

'European allies can no longer assume that the US will provide the necessary military support to defend the continent against Russian aggression,' the report said.

'Were US forces to disengage from the European theatre from mid-2025, Europe’s window of vulnerability would open quickly. 

'Not only would European allies need to replace major US military platforms and manpower – the latter estimated at 128,000 troops – but also address shortfalls in space and all-domain intelligence, surveillance and reconnaissance assets.'

Russia, by contrast, 'could be in a position to pose a significant military challenge to NATO allies, particularly the Baltic states, as early as 2027', the report found.

The IISS report echoed concerns raised in a recent paper by the RAND think tank, which pointed out that the Kremlin is likely to maintain a wartime economy and ability to ramp up military reconstitution efforts even after a ceasefire in Ukraine is agreed.

'Once (the Ukraine war) ends, this shift to a wartime economy, and the attendant effects on the defence industrial sector, will be difficult to reverse without provoking a backlash.

'As a result, Russia's leaders may decide to pursue the permanent militarisation of the Russian economy even after the war ends,' the paper, entitled 'Russia's Military After Ukraine', warned.

It comes as Ed Arnold, a Senior Research Fellow for European Security at the Royal United Services Institute, told MailOnline that policymakers in the West cannot afford to assume that they have years to prepare for a conflict with Russia.

A Russian self-propelled multiple rocket launcher fires towards Ukrainian positions in Ukraine

Russia's economy is on a war footing and will be able to effect a speedy military reconstitution after a ceasefire in Ukraine is agreed

Putin and the Kremlin may be incentivised to maintain a wartime economy even after a ceasefire in Ukraine is agreed

Troops march during the Victory Day parade, held as part of the celebrations of the 80th anniversary of Victory in the Great Patriotic War at Red Square in Moscow, Russia on May 9, 2025

'NATO's a defensive alliance and it isn't going to mount any offensives in Russia, so any conflict would take place based on Russian terms,' Arnold said. 

'What Moscow would try to do is launch a small-scale operation to take a part of a NATO territory and hold it. That would put NATO in a difficult position as to how to respond, whether this would meet the conditions for Article 5.

'If you're Putin, you're going to want to do that when you have a US president who is ambivalent to NATO at best.

'I'm worried about policymakers because they are saying Russia wouldn't be ready for another large-scale conflict in Europe for several years. 

'But something could happen tomorrow that may be an accident or a miscalculation that triggers a much wider conflict.'

This unsettling prospect must be taken into account, particularly given that the war in Ukraine has become a central theme in Russian society, economy and politics. 

The RAND report, which interviewed several senior defence officials in two of NATO's Baltic members - Lithuania and Estonia - highlighted that, unlike European democracies, Russia's military mobilisation is not affected by elections or public dissent.

Russia is operating 'according to wartime rules' with '24/7 defence production', the report said.

As one expert explained: 'If Russia decides to reconstitute, it will... Russia is not worried about the next election and will sacrifice healthcare and other social benefits to divert resources toward military reconstitution... 

'In Russia, "the war has become the political system".' 

The authors of the RAND paper concluded that Russia's economy and industrial base has pivoted to ensure its armed forces can sustain a large conflict indefinitely. 

Even after the Ukraine war is halted, Moscow's efforts to reconstitute and reinforce its military will likely continue apace - an uncomfortable reality that the US and Europe must take into account. 

'The need to scale up defence production as a result of the war in Ukraine may actually lead to a more productive and more skilled defence industrial base,' the report stated.

'Russia's reconstitution process should not be viewed as having a well-defined starting point and distinct end date. 

'In all likelihood, Russia's reconstitution efforts will be a continuous process over the next decade, perhaps longer… Even if Russia falls short of its stated reconstitution objectives in the post–Ukraine war period, it may still decide to initiate another conflict. 

'This means that the United States and NATO should anticipate the necessity of planning to counter a partially reconstituted Russian military.'

Left: The Severomorsk-2 airbase appears to have been refurbished, with helicopters pictured in satellite images. Right: In Petrozavodsk, around 100 miles from the Finnish border, three large warehouses have been built which experts say are storage halls for armoured vehicles

A zoomed-in image shows what appear be the tents set up to house troops in Kamenka near Finland's eastern border

Speculation over European defence readiness comes as NATO foreign ministers on Thursday debated an American demand to massively ramp up defense investment to 5% of gross domestic product over the next seven years.

At talks in Antalya, Turkey, NATO Secretary-General Mark Rutte said that more investment and military equipment are needed to deal with the threat posed by Russia and terrorism, but also by China which has become the focus of US concern.

'When it comes to the core defence spending, we need to do much, much more,' he said.

He also underlined that once the war in Ukraine is over, Russia could reconstitute its armed forces within three to five years, despite the IISS' claim Moscow's forces could be ready to attack as early as 2027. 

The debate on defense spending is heating up ahead of a summit between Trump and his NATO counterparts in the Netherlands on June 24-25. The results of that gathering could well set the course for future European security, including that of Ukraine.

In 2023, as Russia's full-scale war on Ukraine entered its second year, NATO leaders agreed to spend at least 2% of GDP on national defence budgets. So far, 22 of the 32 member countries have done so.

The new spending plan under consideration is for all allies to aim for 3.5% of GDP on their defence budgets by 2032, plus an extra 1.5% on potentially defence-related things like infrastructure - roads, bridges, airports and seaports.

While the two figures add up to 5%, factoring in infrastructure and cybersecurity would change the basis on which NATO traditionally calculates defence spending.

The seven-year time frame is also too long, according to Lithuanian Foreign Minister Kestutis Budrys. He urged his NATO partners to meet the investment goals faster than the 2032 target 'because we see the tempo and the speed, how Russia generates its forces now as we speak.'

Fresh concern over Russia's military posture arose in recent weeks when satellite images from Planet Labs emerged showing a build up of forces just miles from the Finnish border.

The images appeared to show evidence that Moscow has been establishing troop accommodation, aircraft infrastructure and other new facilities at key military bases close to NATO's Eastern and Northern flanks.

A Finnish government report cited in news outlet Iltalehti in December states that Helsinki considers an attack on Finland, Norway, Sweden and the Baltic states to be a possibility.

'Russia is strengthening its military presence and activities in its northwestern direction in all operational environments as quickly as possible,' the report warns. 

NATO sources who spoke to the newspaper reportedly said that Moscow has been rehearsing an attack on the bloc's eastern flank and outlined a threat assessment of where could be targeted.

A coordinated attack involving a number of Russian units could simultaneously strike the Norwegian coast, Finland's south and Lapland region, the Swedish island of Gotland and even break into Estonia, Latvia and Lithuania, the sources are quoted as saying.

But experts have suggested that Putin is more likely to opt for small-scale attacks, designed to destabilise NATO politically as the bloc would be forced to weigh up the risks and costs of entering a full-scale war over a small piece of territory. 

A muzzle flash lights up pine trees as the British Army's Archer Mobile Howitzer gun fires during training near Rovaniemi in the Arctic Circle, Finland, in November

BEFORE: There was little sign of infrastructure in satellite images of the Kamenka site in 2022

AFTER: The Russian army appears to have set up a troop camp in Kamenka, which is around 35 miles from the Finnish border

BEFORE: The previously closed Severomorsk-2 airbase is seen prior to its refurbishment

AFTER: Helicopters are pictured along the runway at the Severomorsk-2 airbase

In 2017, Moscow held seven days of military drills codenamed operation Zapad - Russian for West - which effectively simulated attacks on eastern European states.

The manoeuvres, which involved some 100,000 soldiers according to some Western estimates as well as thousands of armoured vehicles, had the objective of taking over the fictional country of Veshnoriya - with a terrain similar to the Baltic states.

'The Russians have not given up on their attack plan, but want to implement it after the war in Ukraine,' a source reportedly told Iltalehti. 

'According to our information, the plan still exists, and the Russians have not given up on their desire to implement it.' 

Detailing a possible battle plan along the lines of what Moscow has been rehearsing in drills, NATO sources claimed that Russia could attack its western neighbours by land, sea and air.

This could involve sending landing forces to Finnish Lapland, where they could seek to establish a buffer zone and seize strategic locations such as Ivalo Airport.

Moscow could also launch an air attack from the Kola Peninsula and send landing troops into the south of the country. Missiles could also be aimed at Helsinki, it was claimed. 

Russian forces could also launch an attack on the Swedish island of Gotland and attempt to break into Estonia and Latvia.

A breach into Lithuania would likely have the objective of capturing and securing a buffer zone around the Suwalki Corridor - seen as the most likely target by many experts - in order to connect Russia to its militarised exclave, Kaliningrad. 

Pictured: The airbase at Olenya. Russian bombers stationed there have been carrying out raids on targets in Ukraine, according to Kyiv

The Severomorsk-2 airbase was reportedly closed until recently, with helicopters now pictured there in new satellite images

However this threat assessment, seen as a worst case scenario by experts, is based on intelligence information and where Russian army units are currently based.

RUSI's Arnold said that such a large-scale operation would spread the forces Russia has at its disposal too thinly.

'It would be very difficult for Russia to mount a broader assault on multiple targets across NATO's Northern and Eastern flanks,' he told MailOnline.

'But there is a significant possibility of a smaller, more targeted operation mounted by Russia on NATO that is designed to defeat NATO politically. 

'That would put NATO in a difficult position as to how to respond, whether this would meet the conditions for Article 5, etc. That's the only way they could attempt to attack NATO.

'The Russian scenario could be as small as to enter the gap and seize a few miles of territory, widening the gap by a few miles each side. 

'This could sow division and discord in NATO - from one perspective, that's a military incursion on NATO territory that must be defended - but there will be others saying do we want to risk a war with a nuclear armed power over such a small bit of land.'

Arnold said that this kind of small-scale operation was 'likely' to take place, but did not rule out a larger scale conflict erupting.

He pointed out that prior to 2022, 'many would have said that a full-scale of Ukraine is silly, but Putin went ahead and did it anyway.'

Last month, Finland's Deputy Chief of Defence Lieutenant General Vesa Virtanen warned that Russia's actions on the border suggested the the Kremlin was 'deliberately testing NATO's unity' to see if it will trigger Article 5 - the alliance's collective defence clause.

Speaking to German newspaper Welt, Virtanen said Russia has been testing Article 5 with hybrid war tactics including cyberattacks and mass cross-border migration, and is now erecting new equipment to station Russian troops along its border.

'During the war there were about 20,000 soldiers stationed and about four standby brigades, now we see that Russia is building new infrastructure and as soon as they can, more troops in this region,' Virtanen warned.

A Swedish artillery team fires a projectile from an Archer self-propelled Howitzer during the NATO Exercise Lightning Strike on November 20, 2024 near Heinu, Finland

Major Juha Kukkola, a professor at Finland's National Defense University and former platoon leader in the Finnish army, pointed to an important indicator of Russian preparedness in a warning late last month.

'If you see them building new railheads or renovating old ones, it would be good to start paying attention,' he said.

The latest satellite images appear to show infrastructure for vehicles and refurbished airbases.

Recently constructed warehouses are visible in Petrozavodsk, around 100 miles from the Finnish border, which experts suggest are storage halls for armoured vehicles.

In Kamenka, around 35 miles from the Finnish border, more than 130 military tents capable of housing some 2,000 troops are said to have been set up since February.

Pictures from the far north appear to show that the previously closed Severomorsk-2 airbase is now operating, with refurbishment works seemingly completed in recent years. 

Several helicopters are seen parked in bays off the runway, which is situated 110 miles from the Finnish border and less than 70 miles from Norway. 

Meanwhile in Olenya, around 90 miles from Finland, the airbase is said to be fully active, with Russian bombers stationed there carrying out raids on targets in Ukraine, according to Kyiv.

While the bulk of Russia's forces is currently concentrated in Ukraine, Putin is said to be turning his attention towards rebuilding forces in the northwest of Russia.

The Kremlin is planning to build a new army headquarters in the city of Petrozavodsk, around 100 miles from the Finnish border, which would be capable of overseeing tens of thousands of troops in the coming years.

NATO sources reportedly suggested that Moscow could muster an offensive force of 600,000 soldiers near the Finnish and Baltic borders, with their ranks potentially bolstered by troops returning from the frontline once the war in Ukraine ends.

Ian Bond, deputy director of the Centre for European Reform, told the BBC that even if a full ceasefire is agreed in Ukraine, it is unlikely Putin's aggression would be abated.

'Nobody in their right mind wants to think that a European war is around the corner again. But the reality is an increasing number of European intelligence officials have been telling us that,' he said.

'Whether this is coming in three years or five years or ten years, what they are saying is the idea that peace in Europe is going to last forever is now a thing of the past.'

Members of multinational artillery teams stand with an MLRS M270 A2 mobile rocket system during the NATO Exercise Lightning Strike in Finland

Military personnel raise the flag of Finland during a flag raising ceremony after the country's accession to the military alliance in April 2023

NATO could be forced to grapple over whether to honour its mutual defence pact or allow Russia to take territory to avoid a full-scale European war

Ruslan Pukhov, director of Moscow's Center for the Analysis of Strategies and Technologies, warned: 'When the troops are back [from Ukraine], they will be looking over the border at a country they consider an adversary.

'The logic of the last decade shows we're expecting some conflict with NATO.'

Speaking to the US Senate last month, General Christopher Cavoli, commander of US forces in Europe, said: 'The Russian military is reconstituting and growing at a faster rate than most analysts had anticipated. 

'In fact, the Russian army… today is larger than it was at the beginning of the war.'

Russian defence spending has risen to 6 per cent of GDP this year - up from 3.5 per cent at the outbreak of the war in Ukraine in 2022. 

RUSI's Ed Arnold added that he was 'worried about policymakers because they are saying Russia wouldn't be ready for a large-scale wider conflict in Europe for several years. 

'But something could happen tomorrow that may be an accident or a miscalculation that triggers a much wider conflict.'

NATO, faced with threats of funding cuts and accusations of free-loading from President Trump and his officials, has vowed it will 'step up' its contribution to global security as the Russian threat looms.

The military alliance has pushed ahead with increasing its battlefield preparedness with intensive military drills along its eastern flank over recent years, including the annual DEFENDER exercises, which are currently underway in the region.

In southern Finland, the army has reportedly practiced blowing up bridges in case of an invasion.

Amid the war in Ukraine, Putin has said that his aim is to restore all of Russia's 'historical territories', and has compared himself to Peter the Great - the tsar who waged war on Sweden.

Considering how Moscow has carried out its campaign in Ukraine, the Finnish government report is said to have warned that attacks on the civilian population would not be ruled out.

'Russia has shown in Ukraine that it is ready to use large-scale military force against vital targets of society and the civilian population to achieve its political goals,' it reportedly states.

A report by Germany's Federal Intelligence Service (BND) in March warned that Putin is preparing for a conflict with NATO.

According to the BND assessment, Russia could be fully ready for a 'large-scale conventional war' by 2030.

'Russia sees itself in a systemic conflict with the West and is prepared to implement its imperialistic goals through military force, even beyond Ukraine,' the report predicted.

The Royal Navy's Merlin helicopter from 820 Naval Air Squadron, fires flares from HMS Prince of Wales, while embarked for NATO Exercise Steadfast Defender last year

Military vehicles and soldiers parade through Red Square as part of May Victory Day celebrations 

Finland's accession to NATO on April 4, 2023, which extended the alliance's border with Russia by over 800 miles, provoked fury in Moscow.

In response to the Russian neighbour's accession to the block, Putin announced the establishment of the 'Leningrad Military District' near the Finnish border and the deployment of additional military units to the area. 

Last month, former Russian president warned that NATO's newest members are now potential targets of nuclear revenge if Moscow so chooses.

Dmitry Medvedev, who has styled himself as one of Russia's most outspoken anti-Western hawks, appeared to be referring to Sweden and Finland, the last two countries to join the Western military alliance.

If conflict were to arise, nuclear weapons would not be off the table, the TASS state news agency reported.

'The non-aligned status gave them [Finland and Sweden] certain international perks, given their geopolitical position and many other factors,' Medvedev said.

'And now they are part of a bloc hostile to us which means they automatically became a target for our armed forces, including potential retaliatory strikes and even the nuclear component or preventive measures within the framework of a military doctrine.'

Last week, Moscow also warned Britain against deploying a 'coalition of the willing' in Ukraine, declaring it could lead to a nuclear World War Three.