For the offense, one would utilize electronic jamming, electronic deception, directed-energy weapons, and electromagnetic pulse weapons.

CENTERFORSECURITYPOLICY: Center for Security Policy | Chinese Information Warfare: A Phantom Menace or Emerging Threat? | Page: 9

Any electrical or electronic device - including the grid's transformers - not shielded against this pulse would be, at best, taken temporarily off-line.

CENTERFORSECURITYPOLICY: EMP and you