For the Finns, night-time was a friend. With skis on their feet and Mosin Nagant rifles at their backs, they stalked the invaders across those endless December nights, their shots ricocheting off the bark of the birch trees and into the bodies of their foes. The Russians, unable to see their tormentors, wasted time and bullets, firing aimlessly into the mire, even as their opponents slipped away unharmed before returning for yet another raid. Within the space of a single month, from December 1940, these tactics helped destroy an entire Soviet division, its political commissars tearing their insignia from their uniforms as they fled.

The Winter War, the Soviet Union’s agonising invasion of Finland, was an object lesson in how the hours of darkness can be as valuable to a soldier as artillery or tanks. It’s a lesson officers and men have remembered ever since, from the Japanese in the Pacific to the Taliban in Afghanistan. And since the 1940s, of course, fighting by moonlight has become even more effective – thanks largely to the awesome power of night-vision goggles. First popularised in the 1960s, these devices are now commonly used by sophisticated Nato armies and ragtag militias alike.

Yet, even as night vision has transformed global warfare – and will soon represent a market worth over $9bn – there’s plenty of space for improvement. From tiring users to the difficulty of using them in certain weather conditions, goggles can sometimes be inappropriate for some operations. However, if the Finns proved themselves to be consummate night-time fighters in the past century, they’re now developing the kit to flourish in this one too. Dovetailing new goggles with other technologies, helping troops keep in touch with their weapons and their peers, the defenders in the Winter War are leading the way once more. Nor are the Finnish Defence Forces alone. From Norway to the UK, other countries are improving their night-vision capabilities too, with potentially revolutionary consequences for warfare at large.

The night idea

As the Soviets learned more than 80 years ago, winter near the Arctic is often savage and brutal. In December, Helsinki sees only a mere six hours of sunlight a day, a number slumping to practically nil up towards the Norwegian frontier. It therefore makes sense, argues Major Jari Tiilikka, that night vision has become a staple of Finland’s armed forces. That is especially true, continues Tiilikka, an infantry officer in the Finnish army, given the country’s terrain. With thick forests and low hills, training exercises are often intimate, with combatants as close as 50m apart. This, he adds, is the kind of terrain where the “most benefits from dismounted night combat capability can be had”.

If nothing else, this is reflected in the kind of equipment the Finnish army has procured. In his role as programme manager for Finland’s dismounted soldier system, Tiilikka has helped ensure his colleagues have access to a range of night-vision goggles, including thermal observation devices for squads and platoons, as well as sight units for heavier weapons like anti-tank missile launchers. At the same time, this work is shadowed by other militaries nearby. “Norway is well-equipped on the soldier level with night-vision capabilities,” says Lieutenant Colonel Rune Nesland-Steinor of the Norwegian Defence Materiel Agency. “We have it on a fair number of individual dismounted soldiers, and we have also been able to field weapon sights to both soldiers and crew-served weapons.”

Not that the Nordic obsession with night vision can be chalked to climate and landscape alone. For years – but especially since the invasion of Ukraine – defence ministries from Tallinn to Stockholm have been conscious of the Russian mammoth to their east. Finland and Sweden’s recent applications to Nato certainly imply as much, as does the region’s dramatic boost to military spending. In March 2022, to give one example, the Norwegian government announced it would fork out an additional three billion krone ($300m) to “strengthen the defence capability of the armed forces”. When it comes to night vision in particular, it helps that equipment has become so much cheaper over recent years. In the 1990s, only major Nato armies could generally afford to ‘rule the night’, as the saying went. Today, however, the cost has gone down substantially. As Tiilikka says, that means his country can “afford to procure [goggles] in numbers that have a notable effect on our capabilities”.

Yet, if the Nordics now possess a robust mix of night-vision equipment, the machines available to them are far from perfect. That can basically be understood in technological terms. One common type of night vision involves ‘photomultiplying’, essentially amplifying existing light sources, for example flares or stars. But while these devices function well in darkness, the sudden arrival of a new light source – searchlights or explosions among them – risks temporarily blinding the wearer. It goes without saying that this sort of distraction is far from ideal in the heat of battle. Other types of night vision also have problems. Thermal night vision, which detects temperature differences in the infrared spectrum, is ineffective in rain or snow – both things the region enjoys in abundance.

“Norway is well-equipped on the soldier level with night-vision capabilities […] and we have also been able to field weapon sights to both soldiers and crew-served weapons.”

Lieutenant Colonel Rune Nesland-Steinor

Dark and bite

Compared with Lockheed Martin or Raytheon, Senop is hardly a household name. Yet, this Finnish defence contractor, based in a docile business park outside Tampere, is in the process of transforming the country’s night-vision capabilities. A case in point is the firm’s EVA 40 night-vision goggles. Boasting aspheric, high-precision glass optics, and made from state-of-the-art composite materials, the goggles are reputed to be among the lightest around. Nor is that the only area where the Finnish Defence Forces – which hopes to fully deploy EVA 40 goggles by 2024 – is transforming its night-time capabilities. From laser beacons (identifying friends from foes) and laser sights (for aiming weapons), Tiilikka argues for a “significant leap” in what his army can do at night. “Now,” he says, “we have the possibility for each individual rifleman to detect, identify and engage with their personal and squad weapons in the dark.”

The Norwegian army, for its part, is moving in a similar direction. “We are always keeping a close eye on technical developments in the market,” says Nesland-Steinor, adding that blending light-intensifying and thermal technologies has “proved to be beneficial”. All the same, speak to the experts and it becomes clear that this new world of night vision is down to far more than technical wizardry. For starters, Senop didn’t just conjure up its new equipment overnight, but rather worked closely with Tiilikka and his colleagues to make it happen. Among other things, that means the power sources on the goggles are more efficient than they otherwise might have been. Other countries, for their part, have taken similar steps. In the UK, for instance, the Ministry of Defence (MoD) is partnering with Elbit Systems to develop new helmet-mounted night vision systems, with the MoD even boasting an outpost at Elbit’s Kent factory.

Given how sophisticated these devices are, moreover, training is vital to success. Nesland- Steinor is typical when he says that a robust understanding of night vision goggles is key to achieve their “full value”, noting that being so far north gives troops plenty of time to practice over the winter months. Tiilikka makes a similar point. “There is a specific night-combat training course to teach the basics of small unit tactics at night-time,” he explains of his military. “And, after that, our exercise system with systematic field and live-fire exercises include training in low-and-no-light conditions.” The only challenge, Tiilikka adds, is when those endless nights are replaced by the ceaseless days of summer – and darkness is only really possible in a curtained room.

Reality checks

Despite these undoubted successes, it’d be wrong to imply that advances in night-vision technology are flawless. On the contrary, Tiilikka stresses that some of the fundamental limitations of night vision are here to stay. Because of its relative cheapness, for example, he says photomultiplying will “remain the backbone of infantry night combat capability for some time” – despite continued struggles in the face of sudden flashes. On a more fundamental level, meanwhile, Tiilikka notes that nothing but training can make night vision easier to use. Artificially making the night sky shine, he says that some users find it hard to use the machines in practice, adding that headaches and tiredness can be insurmountable side effects for a minority of soldiers.

Yet, if some of the limitations of night-vision goggles show no sign of disappearing, both Tiilikka and Nesland-Steinor are excited for the future. A particular area of interest, they agree, is exploiting the vast potential of augmented reality (AR). Apart from helping distinguish friend from foe, these new systems can offer users other useful information, such as maps or navigation instructions, beamed right onto the goggles as if the wearer were in a video game. Combined with other nifty tools, including the ability to combine low-light and thermal images, it should come as no surprise that armies are rushing to embrace AR. The US military is already investing heavily in the technology, while the Nordics are close behind. As ever, the brutal weather provides both challenges and opportunities, with Tiilikka noting that Finland is currently investigating non-fogging spectacles that don’t mist up in the cold. But given everything he and his team have achieved already, there’s every reason to believe they’ll get there in the end – an ominous development for the grandchildren of those hapless Russian attackers eight decades ago.