The CIP Report
April 2007
2
EMP – A National-Scale Threat to the U.S. Infrastructure
George H. Baker, Associate Director
Institute for Infrastructure and Information Assurance
James Madison University
Since the nuclear weapon atmo-
spheric test days of the 1950s, it has
been known that a single nuclear
weapon detonated at altitudes from
about 30-500 kilometers generates a
strong electromagnetic pulse (EMP)
that can disrupt electronic systems
on the ground at large distances
from the burst. During the Cold
War, the eff ects of high altitude
nuclear detonations were considered
by many to be ephemeral, second
order eff ects in comparison to direct
blast/thermal/radiation eff ects from
near-surface bursts in the context
of mutually-assured-destruction
(or MAD) scenarios. However, as
infrastructure objectives have gained
prominence in military operations,
the likelihood of high altitude
nuclear scenarios have gained wider
acceptance among strategic plan-
ners. When viewed in the context
of infrastructure debilitation, high
altitude nuclear attacks begin to
make sense as a primary tactic to
deny or delay an adversary’s ability
to respond. Th e use of nuclear
weapons at high altitudes could
prove decisive in future confl icts.
Because a national-scale disruption
may accrue from the detonation of a
single weapon, EMP is arguably the
most serious threat to U.S. infra-
structure. Th e EMP induces large
voltages and currents in wires and
antennae connected to electronic
systems that may upset operation or
damage circuit components. Inte-
grated circuits used in computers,
infrastructure controls, and com-
munication systems are particularly
susceptible to these eff ects. Long
line networks such as the electric
power grid and telecommunications
systems receive and propagate the
largest EMP currents, making them
most likely to fail. Th e military has
taken steps to protect its most criti-
cal systems. Th e civilian economy
has not.
In 2002, recognizing our crucial
depe