An EMP is a thermonuclear-based weapon, but it is not a thermonuclear weapon
There is confusion among novices about the difference between an EMP warhead and a thermonuclear warhead. They are not the same.
Though an EMP warhead may be thermonuclear-powered, it is detonated 100 miles above the Earth. The detonation of an EMP does not have to be located near the proximity of its target. The effective radius of a megaton EMP is 1,500 miles. Thus, a detonation 300 miles from the target will be very effective.
A megaton EMP will disable all electronics in a 3,000-mile diameter and fuse the electronics or electrical wiring with 50,000 volts per meter. This renders aircraft carriers and jet fighters (including stealth) useless. This is called a "soft kill" where the opponent's weapons have been neutralized.
A thermonuclear warhead is a different story. It is typically detonated 0.4 miles above the target and incinerates everything within its blast radius. This is a "hard kill" where everything dies in the blast zone.
In conclusion, there is a dramatic difference between an EMP warhead and a thermonuclear warhead. As stated by John Foster (the former head of Lawrence Livermore National Laboratory), China is likely to use a megaton EMP strike to disable an American carrier group.
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U.S. Should Pursue Nuclear EMP Weapon: Ex-Lab Head | Global Security Newswire | NTI
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U.S. Should Pursue Nuclear EMP Weapon: Ex-Lab Head
Feb. 20, 2013
By Rachel Oswald
Global Security Newswire
ARLINGTON, Va. --
One of the United States' most prominent nuclear weapons experts on Wednesday urged the government to develop nuclear weapons that could be used to short-circuit enemies' electrical infrastructure, to counter similar capabilities possessed by Russia and China.
Former Lawrence Livermore National Laboratory head John Foster noted in a speech at the annual Nuclear Deterrence Summit recent claims by Moscow that it has "developed and deployed no-yield clean penetrating EMP weapons tailored to terminate any conventional attack."
"Similarly if the U.S. were to send a naval carrier force to aid Taiwan, the Chinese could use a nuclear EMP weapon to disable the carriers command and control," Foster asserted. "Such declaratory warnings and capabilities cause our allies to question their confidence in our continued deterrence."
Foster, who has long advocated for development of next-generation nuclear weapons, did not cite examples of partner nations that have become skeptical of the strength of U.S. extended deterrence in light of Russian and Chinese offensive EMP capabilities.
"The credibility of our nuclear deterrent would be enhanced if we could develop and certify nuclear weapons such as those described by Russia and China," he stated, adding, that at the minimum the Defense Department and the national nuclear laboratories "should promptly address what capabilities are most needed and if they can be provided without nuclear testing."
Washington's nuclear weapons policy for years has been to not pursue additional capabilities out of concern that would open up new arms races. The United States has maintained a voluntary moratorium on nuclear testing since 1992.
"Yes, some of those capabilities might be considered to be new and would then have to be reviewed by the White House and approved by the president. But that hurdle should not prevent the DOD from requesting what is needed to provide a more credible nuclear deterrent," according to the physicist who led the Livermore site from 1958 to 1965 and subsequently served at high levels at the Pentagon.
The George W. Bush administration was interested in developing a Robust Nuclear Earth Penetrator, which was envisioned as a low-yield nuclear weapon that could destroy enemies' subterranean WMD arsenals without causing significant loss of life. Lawmakers refused to fund work on the weapon in the wake of a congressionally ordered study by the National Academy of Sciences that concluded the warhead could cause massive loss of life as it would not be able to bury itself deep enough in the ground."
