“This exercise is about making the unreal feel real” says Major Hamish Waring as he stares intently at a map dotted with dozens of red, blue and yellow pins. The softly spoken British Army officer is speaking to Monocle in a bunker hidden deep within a forest near Estonia’s border with Russia. Waring’s battalion, the 2nd Scots Battle Group, is taking part in Exercise Hedgehog, the largest-ever military exercise to take place on Estonian soil, featuring more than 16,000 troops from Nato countries including the UK, France, Canada, the US and Sweden. “We’re here to simulate defending Estonia from an aggressor,” Waring adds. The current “aggressors” to which he is referring are Swedish units trying to infiltrate the base. Nato’s newest member applied to join the alliance in May 2022, three months after Russia’s full-scale invasion of Ukraine, and was finally admitted in March 2024. Since then, Swedish soldiers have been attached to Nato’s Forward Land Forces (FLFs), units deployed in advanced positions near the alliance’s 2,500km (1,600 miles) border with Russia. 

It is the FLFs that make up Hedgehog’s personnel and the key aim of the three-day exercise is to improve interoperability. The size and military budgets of Nato’s 32 member states dwarf those of its most likely adversary – but Russia’s forces have the edge in combat experience and the advantage of a common language and military culture. Part of Nato’s challenge in meeting the threat from Moscow is to better integrate its members’ myriad languages, combat systems and procedures. “The biggest challenges are practical,” says Waring. “It might seem small but a misinterpreted message on a battlefield can have serious consequences.” Language adds a layer of complexity that could cause a breakdown in key moments. “The British aren’t the best at languages,” Waring chuckles. “And while many allies speak excellent English, there are nuances – especially in tactical terms – that need clarity.” Lieutenant Colonel Henrik Rosdahl, commander of the Swedish South Skåne Regiment P7, echoes Waring. “We’ve all trained extensively but integrating forces with different languages and cultures is like learning to dance together when you each know different steps.”

Estonia’s position near a heavily populated part of Russia makes it particularly vulnerable to attack. “For Estonia, the threat is real and immediate. These exercises are not theoretical drills but essential preparation,” explains Kristi Raik, a Baltic security expert and director of the International Centre for Defence and Security, a Tallinn-based think-tank. “They signal that Nato is united and ready to defend its members.” The Baltic country has taken serious measures to enhance its defence capabilities since 2022. “Estonia has pledged to up its defence spending to 5 per cent of GDP, which is among the highest [per capita] in Nato,” says Raik. “They’ve also developed rapid-evacuation procedures and integrated their civilian population into defence plans.” Alongside simulated military operations, Exercise Hedgehog also includes an evacuation drill as well as a first-ever test of the nation’s public-alarm system, which simulates how civilians and military personnel would respond to sudden alerts. Everyone with a mobile phone in the country, including Monocle, received a message from the Estonian Defence Forces at 15.00 on 14 May that read, “Public warning system test – no real danger!” The authorities were careful not to incite panic, and the exercise was about testing whether the nation-wide alarm system would work in times of real peril. “It’s about readiness – making sure that everyone knows what to do if the worst happens,” Raik adds. All did not go smoothly, however. There were considerable delays across Estonia in sounding the sirens. The Estonian Defence Forces later admitted that only two-thirds of the alarms triggered on time.

Most Estonians were likely unfazed by the warnings. As in other Baltic countries and Finland, there is a strong sense of crisis preparedness here. More than 80 per cent of the population is in favour of taking up arms to defend the country against an attack, and there’s widespread support for increased military spending and large-scale exercises such as Hedgehog. The combat in Ukraine has demonstrated that modern warfare can be both attritional and technologically advanced. “The conflict has taught us invaluable lessons,” Waring says. “It has shown the importance of rapid deployment, interoperability and sustaining supply chains under pressure.” To that end, the UK maintains a brigade – roughly 5,000 soldiers – on 30 days’ notice to deploy to the Baltic. “We’re ready to move here on short notice to support Estonia and other allies,” he says. The speed of this deployment was also put to the test during Hedgehog. In under 48 hours, a 1,700-strong battle group deployed from the UK to Estonia via rail, sea, road and air. “A credible deterrent requires more than presence – it needs the capability to reinforce quickly and effectively,” Captain Marcus Worthington from the British Army tells Monocle as his platoon of Royal Engineers practises dismantling a roadside improvised explosive device (IED).

The kind of rapid deployment that Worthington is referring to is at the heart of Nato’s plans for the defence of its eastern flank. At the alliance’s 2022 Madrid Summit, it announced a shift in its strategy from the so-called “tripwire” approach to a more robust posture. In practice, this means pledging to radically increase Nato troops’ presence near its borders, meaning that it can deploy soldiers quickly in order to defend every inch of ground from the first hour of an attack, instead of letting territory fall into enemy hands and then liberating it later. It’s a tough ask, as Raik points out, given the hundreds of thousands of troops that Russia would be able to deploy to the Baltics (were they not holed up in Ukraine). “But it’s a step in the right direction”, she admits. “As the war in Ukraine has shown, taking back conceded territory from Russians is challenging”. 

Estonia’s defence strategy relies heavily on reservists, civilians who have completed mandatory military training. In 1991, Estonia introduced compulsory military service for men, today the country has 230,000 trained reservists, nearly one-fifth of the population. Integrating them into Nato is one of Hedgehog’s main objectives. “I did my military service three years ago and was called upon to refresh my training at Hedgehog,” 21-year-old IT student Peeter Lääniste tells Monocle in a makeshift lookout post. He’ll miss two weeks of university, meaning that he will have to make up for lost time by taking several exams – but did not hesitate when called upon. “Living next door to Russia, you have no excuses to stay at home during exercises like these,” he says. While we’re speaking, a squadron of Nato fighter jets booms overhead. Lieutenant Colonel Madis Koosa, who grew up next to an airbase during the Soviet occupation of Estonia, gets visibly emotional. “As a child I used to hate the sound of the Soviet planes but this sound that we just heard, to me that is the sound of freedom.”

At its core, Hedgehog is as much a political exercise as a military one. “We want to show that Nato stands united,” Koosa says. “With forces from across the alliance, including new member states, we want Russia to know that we stand together. An attack against Estonia is an attack against the mightiest military alliance ever to exist.” Despite the unified front, Nato faces significant challenges. Disagreements at the highest level, especially between western Europe and the US, make the alliance appear in disarray. With US military support no longer a cast-iron guarantee, there is a sense that European countries need to shoulder more responsibility by upping defence spending. Then there’s the material factor. On paper, Nato is far superior to its adversary but the fact is that it has never fought a war as a single force. Meanwhile, Russia brings combat experience and troops battle-hardened from combat in Ukraine. “The question is whether Nato’s political will and military readiness will hold up in a crisis,” Raik says. “The exercises are vital but only part of the picture.” 

Is Nato ready for war against Russia? As Raik points out, the consensus among security analysts (at least in this part of Europe), is that a lot depends on how the war in Ukraine plays out. “Putin has made clear that he sees the Baltics as being within the Russian sphere of influence”, she says. “If he has his way in Ukraine, he won’t stop there”. According to Raik, Baltic countries such as Estonia might be next in line. “If Russia sees Nato as weak and not able to defend its Baltic members, it might be tempted to attack”. That’s why exercises like Hedgehog are so crucial. Towards the end of the third day, Monocle meets Fusilier Parker, a fresh-faced 19-year-old Scotsman hiding from drones piloted by Ukrainians with recent battle experience. “This feels more real than any training that I’ve done before,” he says. “But we are ready, come what may”. That, in a sense, is the message that Exercise Hedgehog is hoping to send: that Nato, for all its infighting, is getting better at speaking with one voice.