[A Formerly Proud Canadian]

A nuke on a ship in the Atlantic, fired by missile over/toward N. America, exploded 250 miles up, could ‘fry’ the grid for much of the Eastern US.

Many assumptions but the largest being, this is done outside of NA airspace so as not to trigger an early intercept by US space defences. Ideally (for the Norks), a nuke could be launched that would explode near the centre of the US, destroying all the grid in the US.

They are not interested in ‘winning’ a war because they know they can’t, only in taking the US with them in destruction.

[DiogenesLamp]

A nuke on a ship in the Atlantic, fired by missile over/toward N. America, exploded 250 miles up, could ‘fry’ the grid for much of the Eastern US.

I'm familiar with the theory, but I am not convinced it is as serious as it's advocates claim. We used to explode nukes in space, and they never collapsed our electricity grid.

North Korea has barely gotten 20 kilotons out of their junk so far.