You can initiate effective first strikes with submarines, but they provide no counter to MAD. They're not anti-MAD in any sense -- destruction would still be mu

You can initiate effective first strikes with submarines, but they provide no counter to MAD. They're not anti-MAD in any sense -- destruction would still be mutual. And one of the most assured scenarios of destruction is enemy submarines striking back, even if the other legs of nuclear forces are successfully taken out. Submarines are the hardest to take out, so they are the most pro-MAD.