The results might linger a very long time and effectively disrupt, degrade or destroy electronics for an unknown time period.
In a way, it was designed to mimic the sunspot activity of the 60s that we were unprepared for.
Many scenarios that we ran at RAND began with the high altitude level detonation of such a device over two, maybe three areas of the country, effectively shutting down the entire grid and most communications as well.
The Internet that you are using now was designed in part by Bell Labs - and others - to enable secure communications between the military and the executive branches in just such an attack.
One such pulse lobbed over the great lakes by an offshore sub - today - would throw large parts of the country into chaos, although the Soviet use of such a device would have come from their FOBS system of warhead delivery. (most likely)
I am sure that you are correct in stating that they are working on other ways to achieve the pulse but I am unaware of them.
Thanks for the info, Bill.
You can generate an EMP-like effect with a non-nuclear device, basically an inductor adjacent to an explosive charge, energize the coil and set off the charge, as current cannot change instantaneously in an inductor, the net effect is a rapidly rising voltage waveform akin to the nuclear EMP.
Degradation is another matter, typically that is from neutron radiation altering the lattice structure, not overvoltage stress.
You can defend against EMP if ya know what you are doing ;)
ok back to cloture...