Tarmagon
Murphy was an optimist.
Fair enough. However, we have already established the existence of plasma fields in this universe. Heck, we have decorative plasma globes as desktop toys. This energized plasma field would make an effective defense against the incoming plasma spear by dispersing its effect. It would be less effective against the denser plasma of your NEFP but it would still have an effect. And despite what most people think, getting a nuke to go off is actually quite difficult. And the material is bulky and dangerous in itself. Probably none of these are going to be our go to weapons of choice.