Carl%20Sagan%20-%20The%20Demon%20Haunted%20World

THE DEMON-HAUNTED WORLD
Bethe, the Nobel laureate physicist who headed the Theoretical
Division at the Manhattan Project and who played a major role in
the development of both the atomic and the hydrogen bombs,
attests that Teller's original suggestion was flawed, and that the
work of many people was necessary to bring the thermonuclear
weapon to reality. With fundamental technical contributions from
a young physicist named Richard Garwin, the first US thermonuclear
'device' was exploded in 1952. It was too unwieldy to be
carried by a missile or bomber; it just sat there where it was
assembled and blew up. The first true hydrogen bomb was a
Soviet invention exploded one year later. There has been debate
on whether the Soviet Union would have developed a thermonuclear
weapon if the United States had not, and whether a US
thermonuclear weapon was even needed to deter Soviet use of
their hydrogen bomb, since the US by then possessed a substantial
arsenal of fission weapons. The preponderance of current evidence
is that the USSR, even before it exploded its first fission
bomb, had a workable design for a thermonuclear weapon. It was
'the next logical step'. But Soviet pursuit of fusion weapons was
much aided by the knowledge, from espionage, that the Americans
were working on them.
From my point of view, the consequences of global nuclear war
became much more dangerous with the invention of the hydrogen
bomb, because airbursts of thermonuclear weapons are much
more capable of burning cities, generating vast amounts of smoke,
cooling and darkening the Earth, and inducing global-scale
nuclear winter. This was perhaps the most controversial scientific
debate I've been involved in (from about 1983-90). Much of the
debate was politically driven. The strategic implications of nuclear
winter were disquieting to those wedded to a policy of massive
retaliation to deter a nuclear attack, or to those wishing to
preserve the option of a massive first strike. In either case, the
environmental consequences work the self-destruction of any
nation launching large numbers of thermonuclear weapons even
with no retaliation from the adversary. A major segment of the
strategic policy of decades, and the reason for accumulating tens
of thousands of nuclear weapons, suddenly became much less
credible.
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