The Russian military has confirmed that a test-firing of its Bulava (SS-NX-30) submarine-launched ballistic missile (SLBM) from the White Sea on Dec. 23 failed. This means that the Bulava — the core project of Russia's second-strike capability and its strategic fleet — has now failed in five out of eight trial launches from submerged submarines. Second-strike capability refers to the ability to threaten nuclear retaliation even after one has suffered an overwhelming nuclear strike. Second-strike is meant to discourage a nuclear-armed opponent from launching an overwhelming nuclear attack against one's nuclear facilities, in the hopes of destroying all nuclear retaliatory capacity. Nuclear-powered ballistic missile submarines create this capability by being able to keep their location covert and launch SLBM's even after their country and land-based intercontinental ballistic missiles (ICBMs) have been attacked.