Ukrainian strikes on Crimea are having major psychological and operational effects on Moscow’s forces, Western officials have told journalists.
Explosions at the Saki airbase on 9 August and other assaults have put more than half of the Black Sea fleet’s naval jets out of action, they said.
The fleet has a revered history, but it has suffered a series of humiliations since the invasion began in February.
Officials said the setbacks have forced it to adopt a defensive posture.
In March, the fleet’s flagship, the cruiser Moskva, was sunk by Ukraine. The 510-crew missile cruiser had led Russia’s naval assault on Ukraine, and its sinking was a major symbolic and military blow.
At the time, the Russian defence ministry said ammunition on board the Moskva exploded in an unexplained fire, and the ship tipped over while being towed back to port.