It's the Swedish submarines he has to worry aboutr.
From Reuters via gCaptain, July 25:
The Russian navy can detect any enemy and launch an “unpreventable strike” if needed, President Vladimir Putin said on Sunday, weeks after a UK warship angered Moscow by navigating near the Crimea peninsula.
“We are capable of detecting any underwater, above-water, airborne enemy and, if required, carry out an unpreventable strike against it,” Putin said speaking at a navy day parade in St Petersburg.
Putin’s words follow an incident in the Black Sea in June when Russia said it had fired warning shots and dropped bombs in the path of a British warship to chase it out of Crimea waters.
Britain rejected Russia’s account of the incident, saying it believed any shots fired were a pre-announced Russian “gunnery exercise,” and that no bombs had been dropped....
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In 2005, the USS Ronald Reagan met its match in the form of a single, diesel-powered Swedish submarine. During war games, the plucky submarine was able to sneak through the passive sonar defenses ...
Of course there was this to throw into the mix:
