Yeah that's my point. If the vulnerability relies on nukes then is it even a vulnerability? If nukes are being exchanged that's game and it's a moot point.
Is it? I thought about it like that for a long time also. But nowadays i think think this thought applied to the 'city killers' on or slightly above ground only.
OTOH there are many satellites up there whose missions are unknown (to us). Who is to say that some party wouldn't try it, maybe during a geomagnetic storm? Or, maybe some crazy like NK because, hey, got china watching my Six!1!!
Of course the orbits, and therefore the owners are known.
This does not need to be 'high tech' in the way some understand rocket science or reentry vehicles to be.
Just some crude device which survives start and waiting 'up there', then being ignited later, without the complications of reentry heat and burn.
Miles of copper wire, thick titanium tube, large neodymium magnet, and C4. The hard part is the simulations/experimental design of the titanium part such that the exploding C4 and melting wire don't disintegrate the whole device before the magnet has had a chance to pass through the whole coil.
Last time I did the math though, you'd only get a few tens of kilometers of effect radius with an 20ft shipping container sized device so realistically, EMPs are only deployable using nuclear weapons detonated in the atmosphere.
That's more than a few EMP's...
Of course if they deploy it on a single Digital Ocean droplet then it's a bit more vulnerable.