A top military official has claimed that Nato is more than a decade behind Russia's military capabilities, months after a British brigade was wiped out by a Ukrainian unit in war games. Last year, the UK took part in a war simulation in Estonia involving more than 16,000 troops from 12 Nato countries but were 'destroyed' by Ukrainian troops in a 'horrible' defeat. The embarrassing loss came only months before Ukraine’s former commander-in-chief warned that it will take more than a decade for Nato to catch up to half of Russia’s military capabilities. However, Mr Zaluzhny conceded that Ukrainian armed forces required air defence systems as well as other technology that Nato members possess. The simulation underscored the importance of drones as the defining weapon of the Ukraine war, with analysts estimating the drones are responsible for approximately 70 per cent of casualties.