Russia will be able to sustain its invasion of Ukraine throughout 2026 even allowing for emerging manpower and economic pressures, while its missile and drone threat to Europe is growing, according to a leading military thinktank.
Bastian Giegerich, the director general of the International Institute of Strategic Studies, said there was "little indication" that "Russia's ability to continue its war against Ukraine for a fifth year is diminished".
The thinktank reported that the Kremlin spent at least $186bn (£138bn) on defence in 2025, an increase of 3% in real terms, amounting to 7.3% of the country's GDP - more than double the proportion spent by the US and about three times the level of the UK.
Fenella McGerty, a defence finance expert with the thinktank, said that while Russia's economy was slowing, which could lead to "a potential decline" in real-terms military spending in 2026, it had to be set against several years of sharp growth.
Military spending "had doubled in real terms since 2021", she emphasised, allowing Russia to spend more heavily on military equipment and recruitment to sustain relentless ground and air attacks against Ukraine in the immediate future.
Four years ago, Vladimir Putin launched the full-scale invasion of Ukraine. Though Russia's smaller neighbour did not collapse, the Kremlin reoriented to a war economy and continued to fight with high intensity despite sustaining more than 1.2 million casualties killed and wounded.
"Despite western conversations about a sustainable ceasefire agreement, Russia intensifies its attacks on Ukraine's critical infrastructure and population centres with a mix of cruise and ballistic missiles and one-way attack UAVs [drones]," Giegerich added.
Nigel Gould Davies, a Russia expert at the thinktank, said there were "growing signs that Russia's rate of recruitment has begun to fall short of its monthly losses" on the battlefield, though Moscow has the ability to cut its casualty rate by reducing the tempo of its offensives across the Ukrainian frontline.
Gould Davies, a former UK ambassador to Belarus, said if that trend were to be continued it could eventually force the Kremlin to "a moment of truth" where it would have to risk a second enforced mobilisation and risk the scale of social unrest seen during the enlistment of September 2022.
Russia recruits an estimated 30,000 to 35,000 people a month, though Gould Davies said he believed its forces' quality was dropping because recruiters were having to turn to "the alcoholics and the drug addicted, and the frankly sick".
Estimates of Russian casualties are variable. Figures released by the UK MoD earlier this month suggested Russia incurred 35,030 casualties in December and 31,713 in January, somewhat lower than the "nearly 40,000 a month" cited by western officials in a briefing on Monday.
Moscow is also using the war to develop new battle tactics and missiles and attack drones, the thinktank said, including a modernised Shahed-136 that could strike targets across Europe to a range of 2,000km, as part an overall military modernisation.
Giegerich said that underscored the need for Nato "to increase investments in missile defence and anti-drone systems", the need for which was demonstrated when 21 Russian drones crossed into Poland last September, closing several airports and forcing people in three regions to be told to shelter indoors.
European Nato allies and Canada promised to increased defence budgets to 3.5% by 2035 last summer in response to the growing Russian threat, and demands from the Trump administration that the continent takes primary responsibility for its own security.
But the IISS, in its annual review The Military Balance, cautioned that would required "sustained and significant investments" that many Nato allies would find hard to reach, given it could require spending cuts and trade off elsewhere.
Europe would also take "well into the 2030s" to reduce its military dependance on the US, Giegerich said, because it remained dependent on an unpredictable White House for military intelligence, cloud computing and space assets. Improving air defence was also a priority, he added.