"EMP Threat: fact, fiction and response", an article by Yousaf Butt at The Space Review, examines the threat of a catastrophic electromagnetic pulse. The present writer finds, in recent years, attention to this issue noteworthy. "Report of the Commission to Assess the Threat to the United States from Electromagntic Pulse (EMP) Attack", published in 2004, provides the recommendations of an EMP Commission. Butt's Space Review article addresses the commission's concerns about damage to the infrastructure, electronics and reviews results of high altitude nuclear explosions from 1955-62. The US series of tests called Starfish Prime and Russian series, which includedTest 184, are specifically reviewed.
Butt breaks down three properties of a gamma ray burst from nuclear detonation and resultant pulse: E(1-3). E-1 and E-3 are most damaging to electronics, while properties of E-2 resemble lightning. A terrorist group could detonate a low yield nuclear device at an altitude of 40 to 100 km, which would be crippling to a nation's infrastructure and electronics. A low yield device would result in a pulse low in E-3 but still deliver sufficient E-1 energy to prove damaging. Today's electronics based on integrated circuits are one million times more vulnerable to pulse damage than the vacuum tubes used in the cold war era at the time of the high altitude nuclear detonations.