True, but misleading.
I don't know the math, but the exact same effects over much smaller specific areas are possible. If I remember right, in the past there have been tactical (battlefield) EMP weapons studied and tested.
Also true, is that to render an area the size of the US,Russia, South America or Africa is unpractical.
Plus, I am sure that the universal sandmaggot rules for the entire universe, the queeran, somewhere must contain the prohibition about exploiting physical laws discovered and exploited by unbelievers...
Gee, I thought their nuclear program was for peaceful purposes.