It's not just nuclear bombs. Contra idunnoman1222's confidently wrong declaration, what anfractuosity referred to is well-established stuff around for decades,

It's not just nuclear bombs. Contra idunnoman1222's confidently wrong declaration, what anfractuosity referred to is well-established stuff around for decades, not some weirdo fringe thing: https://en.wikipedia.org/wiki/Explosively_pumped_flux_compression_generator https://en.wikipedia.org/wiki/Explosively_pumped_flux_compre... A lot of sci fi has "EMP grenades". I don't believe they've been declassified but I'd bet something like them exist. Whether they're quite down to "grenade" size I don't know, though my gut leans "yes". Most people's intuitions about what is possible in what volume of space are tuned for machines we want to be able to use and reuse. If you don't mind destroying the machine in the process, which you've already accepted if you're using the explosively-pumped flux compression generator, you have some options for generating a lot of charge very quickly in a small space, and there are people with experience using them in other applications out there to be hired.