For nearly 20 years, the secret code to authorize launching U.S. nuclear missiles, and starting World War III, was terrifyingly simple and even noted down on a checklist.
The Permissive Action Link (PAL) is a security device for nuclear weapons that it is supposed to prevent unauthorized arming or detonation of the nuclear weapon.
JFK signed the National Security Action Memorandum 160 in 1962 that required all nuclear missiles to be fitted with a PAL system.
But nuclear experts claim the military was worried about the possibility of command centers or communication lines being destroyed in real nuclear war, stopping soldiers getting the codes or authorization to launch missiles when they were actually needed.
So they simply left the security code for the weapons as eight zeros, getting around the security safeguards.
Dr. Bruce G. Blair, worked as a Minuteman launch officer between 1970 and 1974. He has written several articles about nuclear command and control systems.
In a paper called Keeping Presidents in the Nuclear Dark, he wrote that Strategic Air Command 'remained far less concerned about unauthorized launches than about the potential of these safeguards to interfere with the implementation of wartime launch orders.'
Incredibly, he also writes that the vital combination for America's nuclear deterrent was even helpfully noted down for the officers.
'Our launch checklist in fact instructed us, the firing crew, to double-check the locking panel in our underground launch bunker to ensure that no digits other than zero had been inadvertently dialed into the panel,' Dr Blair wrote.
According to Today I Found Out, Blair wrote an article in 1977 entitled The Terrorist Threat to World Nuclear Programs.
This claimed that it would take just four people working together to launch nuclear missiles from the silos he had worked in.
That very same year all the PAL systems were activated, and the nuclear codes were changed. Hopefully to something more complicated than 00000000.
综合外国媒体12月1日报道，核导弹发射密码一向是美国的最高机密，然而在过去近20年的时间里，该密码竟然只是极其简单、极易被破解的“00000000”。
1962年，美国时任总统约翰·菲兹杰拉德·肯尼迪签署法令，要求所有核导弹配备“准予行动”（Permissive Action Link）装置。这是一套需取得授权才可发射核导弹的安全系统，确保在发射官输入正确密码后，才会发射核导弹。
根据核专家的说法，美国军方担心核战争爆发时，指挥中心和通讯线路可能被毁坏，导致士兵在真正需要发射导弹时却无法取得核密码，由此他们决定把核密码设为最简单的“00000000”。
布鲁斯·布莱尔曾在1970年至1974年间担任“民兵”核导弹发射官，他在一篇文章中写道：“相较于未经授权发射核导弹，（美国）战略空军司令部更担心密码太复杂而无法实时响应导弹发射命令。”
更加令人难以置信的是，布莱尔透露，发射清单上 甚至间接说明了至关重要的核密码只能是由数字零组成。“发射清单上清楚写明，发射官应当仔细检查位于地下发射舱里的锁定操作面板，以确保不会有人不小心地 输入除了零以外的其他数字。实际上，这是在告诉我们，密码里只能有数字零。”
此外，布莱尔还表示，在他担任核导弹发射官时，发射核导弹只需要4个人协力合作。而1977年所有核导弹配备的“准予行动”装置均被激活后，自1962年被启用至此时的“8个0”核密码终于更改。