W70

W70 was a two-stage, thermonuclear warhead that was developed for the MGM-52 Lance missile by the United States. Designed by Lawrence Livermore National Laboratory, the Mod 1 and Mod 2 version of the weapon entered service in 1973, while the enhanced radiation Mod 3 weapon entered service in 1981. The last W70 warhead was dismantled in February 1996.

Design

Declassified British documents describe the Mod 1 and Mod 2 versions of the weapon as having three yields between, while the Mod 3 enhanced radiation version was estimated to have a yield of The Mod 1 reportedly had more yield options than the Mod 2 warheads. The Mod 3 was reportedly 40% fission and 60% fusion, with two yield options. The weapon weighed, and was long and in diameter.
Mod 1 and 2 weapons were produced from June 1973 to July 1977, while Mod 3 weapons were produced from August 1981 to February 1983. 900 Mod 1 and 2 warheads and 380 Mod 3 warheads were manufactured. The last warheads were retired in September 1992.
The weapon was the successor to the previous proposed Lance warhead, the W63. The weapon used a category D Permissive [Action Link] and had command disable, but lacked insensitive high explosives and enhanced nuclear detonation safety.
The inventor of the neutron bomb, Samuel Cohen, has criticized the description of the W70 as a "neutron bomb":

the W-70... is not even remotely a "neutron bomb." Instead of being the type of weapon that, in the popular mind, "kills people and spares buildings" it is one that both kills and physically destroys on a massive scale. The W-70 is not a discriminate weapon, like the neutron bomb—which, incidentally, should be considered a weapon that "kills enemy personnel while sparing the physical fabric of the attacked populace, and even the populace too."