@9485605b The Rosenberg's shared detailed plans for how to build an atomic bomb, including how to make shaped charges for implosion and the trigger. These remain highly classified secrets because it's crucial to the construction of a weapon.

Not defending Trump here, because if he did share secrets on submarine capabilities, as reported, it's a huge loss to the US deterrence and could help in a surprise first strike. 

But let's not devalue the damage the Rosenbergs did.