The year 2025 is shaping up to be another consequential one for European defense. Five weeks after US President Donald Trump’s second inauguration, Russia’s full-blown war against Ukraine will reach its third anniversary. European states are concerned about what the second Trump administration will mean for Ukraine’s defense against Russia, and also about Washington’s future commitment to NATO. Prompted by worries over Russia, Europeans are spending more on defense and have embarked on the long road to strengthening their military capabilities. And it is certain that Trump will press them to do still more, and faster.
One problem for European governments is that of timelines: whether their military readiness will have recovered enough by the time Russia’s army has been rebuilt from its mauling in Ukraine to the stage whereby it can again pose a direct challenge to NATO. Estimates voiced by some European military professionals vary from five years to just two-to-three years. Another challenge for European governments is one of political focus: that they sustain policy attention—and funding—on defense even if today’s proximate problems abate, particularly if there is some form of settlement in Ukraine.
Indeed, the defense challenge European governments face is not solely military, nor indeed one that emanates from Russia alone. An important development arising from the war in Ukraine has been the impact on European security of military capabilities from Asia and the Middle East, with North Korean troops now fighting in Russia and Russia’s inventory boasting weapons from that country and Iran.
The developing “no-limits” partnership between Russia and China, with some of Moscow’s military equipment reportedly featuring Chinese-origin components, is a further concern. And as some European states aim to quickly rebuild their military capability in response, they are looking beyond traditional suppliers to include, for instance, Israel and South Korea.
A further aspect has been a greater focus on security as an integral facet of defense, such as security of supply and security of critical infrastructure even if—similar to awareness of the military capabilities required to meet NATO obligations today and the investments needed for future military challenges—this is far from new.
Hybrid Threats Are Nothing New
The December 26, 2024, announcement by authorities in Finland that they were investigating the disruption caused the day before to the Estlink-2 power connector between Finland and Estonia, and to telecommunications cables, was the most recent manifestation of threats to Europe’s critical infrastructure.
Personnel from Finland’s border guard and military boarded the Eagle S, a tanker registered in the Cook Islands but alleged to be part of Russia’s “dark fleet,” and moved the vessel to Finnish territorial waters. Finnish and Swedish investigators later raised an anchor from the seabed and conducted tests to determine whether it was from the Eagle S. They alleged that the cable damage had been caused by an anchor dragging. Indeed, there appeared to be a roughly 100-kilometer-long drag-track, and the Eagle S was missing one anchor.
This is only the most recent allegation that Russia-linked actors have been conducting activities directed against critical infrastructure targets in Europe, including that they have carried out reconnaissance as well as attacks or that attempts have been thwarted by law enforcement authorities. There have been maritime reconnaissance activities by Russian vessels, other pipeline and cable incidents, and, in the United Kingdom, charges of espionage and arson, leading Ken McCallum, the head of the UK’s domestic intelligence agency, MI5, to say in October 2024 that Russian military intelligence (GRU) agents “had carried out ‘arson, sabotage and more dangerous actions conducted with increasing recklessness’ in Britain.”
Allegations have also been made that Russia-linked actors have plotted to assassinate a leading German defense industrialist and carried out an arson attack against German missile manufacturer Diehl, while arrests have been reported across Europe of individuals suspected of espionage or sabotage operations linked to Russia, alongside episodes such as the attribution of malicious cyber activity to a specific Russian GRU unit.
These alleged attacks of course take place within the context of Western support for Ukraine, and to a degree it should perhaps be expected that Russia’s security services would look to utilize levers available to them. Espionage and reconnaissance operations should not surprise, but there have been other deeply concerning activities that not only predate the current level of Western support for Ukraine, but also predate Russia’s invasion itself, namely the chemical weapon attack in the UK on Sergei Skripal and his daughter, and the poisoning with a radioactive substance of Alexander Litvinenko.
Alongside allegations that Russian-linked vessels have damaged critical infrastructure in Europe, however, Chinese vessels have also come under scrutiny. In November 2024, a Chinese-flagged bulk carrier, the Yi Peng 3, was suspected of severing two fiber-optic cables in the Baltic Sea, while a month earlier the Hong Kong-flagged container ship Newnew Polar Bear damaged the Balticconnector gas pipeline.
More Complex Military Challenges
China’s support for Russia’s war in Ukraine, albeit still limited, includes material useful for military purposes. In April 2024, then-US Secretary of State Anthony Blinken said that “70 percent of the machine tools that Russia is getting from abroad [is] coming from China; 90 percent of the microelectronics.” Further details were given by the former US deputy secretary of state, Kurt Campbell, in September 2024. “Chips, some design features, some capacities associated with the making of explosives” have supported Russian battlefield operations. He continued, “We see the role of UAVs [unmanned aerial vehicles, or drones] and other capacities that are penetrating the Ukrainian airspace. Much of that has been supported surreptitiously by China.”
Nonetheless, Russia has also reshaped its defense industry and economy to support its war, and its forces continue to receive new equipment. IISS analysis in The Military Balance 2025 indicates that Russia’s total military expenditure grew by nearly 42 percent in real terms between 2023 and 2024. Its defense industry is working around the clock to try to make good the materiel losses from the war, which for the ground forces at least still includes upgrading some old armor from storage sites—even if the available numbers there are dwindling. It is possible that an industry now operating at a relatively high tempo could shift to reconstituting the ground forces, if hostilities in Ukraine were to cease and plans were in place.
Meanwhile, deliveries of combat aircraft also continue. The Russian air force may have lost around 31 of its inventory of Su-34 Fullbacks, but around 27 new-build Fullbacks have been delivered and the air force has finally been introducing the new multi-role Su-57 fighter. And while ammunition and UAV shortfalls may have led to deliveries from Iran and North Korea, Russian manufacturers are still delivering. In particular, the country’s use of cruise and ballistic missiles against Ukrainian targets constitutes a worrying portent of the capabilities that could face European states in a potential future conflict.
In November 2024, Russia’s use against the Ukrainian city of Dnipro of what appeared to be an intermediate-range ballistic missile, employing multiple warheads, was perhaps designed more to focus minds among Ukraine’s external supporters than it was to achieve battlefield effect. While President Vladimir Putin said this was a new system, dubbed Oreshnik, Western analysts thought it more likely a modified version of the developmental Rubezh (RS-SS-X-28) weapon.
However, some of the new systems announced by Putin in 2018 have started to enter the inventory. Little has been seen publicly of the Burevestnik nuclear-powered cruise missile and the Poseidon nuclear-powered long-range torpedo, but the Avangard hypersonic glide vehicle (RS-SS-19 mod 4 Stiletto) is currently in service with two Intercontinental Ballistic Missile (ICBM) regiments, the Kinzhal (RS-AS-24 Killjoy) air-launched ballistic missile has been used against targets in Ukraine, and tests continue of the Tsirkon sea-launched hypersonic missile.
Russia’s ground forces may have been mauled in Ukraine, but the country’s military capability remains substantial. Russia’s main naval formation, the Northern Fleet, has been virtually untouched by the conflict. It contains much of Russia’s strategic nuclear capability in its ballistic missile submarines. And Russia has just commissioned the fourth Yasen-M guided-missile submarine (making five overall, including the prototype Yasen). Three Yasen/Yasen-M boats are now with the Northern Fleet.
Russia remains the immediate concern for many Western countries. At the same time, however, some countries are designing their military systems with an eye to the military developments taking place in China. An example is the UK-Italy-Japan Global Combat Air Programme, which is designed to produce a next-generation air platform to replace the British and Italian Typhoon combat aircraft and Japan’s F-2 fighter. While Moscow may have been modernizing its military power, its ambitions have nonetheless suffered because of the war.
China’s Military Modernization
There are no such wartime restraints on China’s military modernization, and its visible progress has been striking—the air domain is a good example. At the end of 2024, China not only unveiled the J-35 variant designed for its air force, but it showed two previously publicly unknown combat aircraft designs.
It has long been known that China’s military modernization is the “pacing challenge” for the US armed forces, against which it has been considering not only future equipment plans but also future force design and doctrine. For European nations looking to maintain high-end interoperability with US military systems, and for European defense industries looking to export advanced military systems to customers eyeing potentially demanding high-threat military scenarios, it may also make sense to design against these potential threat systems.
Beijing seems to hold ambitions to deploy its own forces further afield, certainly its maritime forces. But while its navy has been making periodic deployments to European waters since the beginning of this century, its ability to deploy at scale is probably still limited in the short term. However, the increasing co-operation between the Chinese and Russian navies will pose problems for NATO naval planners and worries about possible defense technology exchanges.
At the same time, China’s military systems are being sold to more international customers, meaning that NATO or EU member states’ military forces deployed abroad could encounter Chinese-designed military equipment. Moreover, advanced Chinese systems have already arrived in Europe: Serbia in early 2024 said it had completed fielding the Chinese FK-3 (HQ-22; CH-SA-20) air defense system.
Maintaining Long-term Attention
In military terms, the challenge is stark. An important aspect of Russia’s military campaign in Ukraine has been its use in the war of cruise and ballistic missiles and UAVs. These threats come high and low, fast and slow. Though Europe divested much of its air defense after the end of the Cold War, investments are again underway, with proximity to the threat proving an incentive for Baltic, Nordic, and East European states.
Elsewhere there seems less urgency, but the fact remains that Russia’s cruise missiles—with 2,500-kilometer ranges—could put much of Europe at risk, not only those countries close to its borders. Procurements are underway of US-designed air defense systems, as are various initiatives to improve ground-based air defense with European solutions, but here it will be important to reconcile potentially differing military requirements and industrial expectations.
Air and missile defense is an example of where policies and priorities are changing. Ammunition production is another, as NATO and EU states have ramped up production to aid Ukraine’s defense. Here the statistics are noteworthy, but so too are some of the challenges that are affecting European states’ rearmament plans. The US maintained significant stockpiles of 155mm shells, many of which it has given to Ukraine. This stockpile gave America’s industry time to ramp up production. But even so, US production had already dropped, with Reuters reporting in July 2024 that “from summer 2014 to fall 2015, the US added no new shells to its stockpile.” More recently, in November 2024, Douglas Bush, then-US assistant secretary of the army, told the IISS Prague Defense Summit that the US has “a path to ‘100,000 a month in 2025’” with contracts “already in place.”
In Europe, reduced production capacity has made rapid expansion harder and, while orders may give manufacturers the confidence to make investments, it will take time to reach the desired production levels as companies compete for skilled workers and materials. Nonetheless, investments by the German firm Rheinmetall, for example, have led it to emerge as the leading manufacturer of howitzer ammunition in Europe, and its production capacity is set to expand to 1 million shells per year globally by 2026.
European states de-prioritized defense after the end of the Cold War. Funding was reduced, forces and inequipment shrank in number, stockpiles decreased, and industry contracted. Russia’s war against Ukraine and worries about Moscow’s military capability and intentions have spurred NATO and EU member states to increase funding, with European states now spending over 50 percent more in nominal terms than in 2014, and it is almost certain that President Trump will exhort European states to spend more.
There remains a long way to go in building back Europe’s defense capacity. Key challenges will be enabling armed forces to regenerate and refill stockpiles where appropriate, and giving industry the certainty needed to restart or maintain production lines. However, none of this is new.
Another aspect that is not new is the need to focus once more on security and resilience, taking account of industrial and technological change, such as the raw materials now found in modern defense equipment, and vulnerabilities to cyber threats. Here there has been some progress, with task forces now focusing on critical infrastructure and greater attention paid to civilian resilience and security of supply, but again, responses vary.
Armed forces, too, need to be resilient, with societies better informed not only of security risks, but of the investments that are required. The decisions to reduce Europe’s capabilities were political choices. The same applies now, but rebuilding Europe’s defense capacity will also raise uncomfortable questions of prioritization. Sustained political attention and appropriate funding will be key.
James Hackett is head of defense and military analysis at the International Institute for Strategic Studies (IISS).
