On Wednesday, over tea and cakes with veterans of the Ukraine war, President Vladimir Putin announced Russia had tested a new weapon.
"There is nothing like this," the Russian leader said of the Poseidon - a nuclear-powered, nuclear-capable underwater drone that can be fired like a torpedo and which a senior Russian MP said could "put entire states out of operation".
When it was first unveiled in 2018, Russian media said the Poseidon would be able to achieve a speed of 200km/h (120mph) and travel in a "constantly changing route" that would make it impossible to intercept.
Putin's claim came only days after the announcement that Moscow had conducted a test of its "unlimited-range" Burevestnik nuclear-powered cruise missile.
It's "a unique product, unmatched in the world", Putin said of the Burevestnik, noting the missile was so new "we are yet to identify what it is, what class of weapons [it] belongs to".
