You are probably right about Israel. They don’t need to put a nuke down into a city. The real question is can they make one this small.
A single small bomb in high orbit (200 miles) would be enough to take out the electronics on the eastern half of the US.
They know this.
You’d need a bomb that was about a megaton and a fusion bomb at that. And another issue...exploding it on the nightside verses the day side since the energy from the sun pushes the bulk of the magnetic field to the night side. (think like the tail of a comet) You get more bang for your buck on the night side.