Ukraine’s domestic security service, the SBU, said Monday that it struck a Russian submarine in the Black Sea port of Novorossiysk, causing critical damage to the vessel and effectively disabling it.

The Russian Typhoon-class SSBN (Project 941 "Akula") is the largest nuclear-powered ballistic missile submarine ever built. Designed during the Cold War to counter the U.S. Navy’s Ohio-class SSBNs, it ...

The introduction of the submarine to naval warfare reshaped planning and doctrine. While typical engagements relied on guns ...