Russia will be able to sustain its invasion of Ukraine throughout 2026 despite emerging economic and manpower pressures, according to a leading military thinktank. The International Institute for Strategic Studies (IISS) said there was little indication that Moscow's ability to continue the war for a fifth year was diminished.
The thinktank reported that the Kremlin spent at least $186bn (£138bn) on defence in 2025, a 3% real-terms increase, amounting to 7.3% of GDP—more than double the proportion spent by the US and about three times that of the UK. While Russia's economy is slowing, defence finance expert Fenella McGerty noted that military spending had doubled in real terms since 2021, allowing sustained heavy investment in equipment and recruitment.
Russia continues to intensify attacks on Ukraine's critical infrastructure and population centres using cruise and ballistic missiles and drones. The IISS warned that Moscow is developing new battle tactics and weapons, including a modernised Shahed-136 drone with a range of 2,000km, capable of striking targets across Europe.
However, there are signs of strain. Russia expert Nigel Gould Davies said recruitment rates have begun to fall short of monthly losses, which are estimated at around 30,000-35,000 casualties per month. He warned that if the trend continues, the Kremlin may face a difficult choice between a second enforced mobilisation, risking social unrest, or reducing the tempo of offensives.
The IISS said the growing threat underscores the need for Nato to increase investment in missile defence and anti-drone systems. European allies and Canada have pledged to raise defence budgets to 3.5% of GDP by 2035, but the thinktank cautioned that this would require sustained and significant investments, and that Europe would take well into the 2030s to reduce its military dependence on the US.
