How PALS Help Secure Nuclear Weapons

Hugh Pickens writes "The BBC reported last week that until 1998 no code or dual key system was required to arm British nuclear weapons. Bombs were armed by inserting a bicycle lock key (video) into the arming switch and turning it 90 degrees. Permissive Action Links (PALs) were introduced in the 1960s in America to prevent a mad General or pilot launching a nuclear war on their own and to control nuclear weapons that were at least partially controlled by other nations but as late as 1974, when an armed quarrel broke out between two members of NATO, Greece and Turkey, the Secretary of Defense learned that many tactical nukes were still not equipped with PALS. It has been reported that PALs have been installed on Pakistan's nuclear weapons to disarm or disable their triggering mechanism if the wrong code is entered or if the bomb is tampered with in any manner."

Comments

Re:Quite sensible

[sseaman]

I suspect it has less to do with fear of rogue generals illegally declaring war against other countries as it does with generals illegally declaring war against their own commander in chief. Surely no one understands better than Pervez Musharfaf that generals don't always voluntarily obey their President.

the PAL system was neutered by US generals

[SuperBanana]

Permissive Action Links (PALs) were introduced in the 1960s in America to prevent a mad General or pilot launching a nuclear war on their own

Wow, that glosses over reality very nicely. The codes were all zeros until the 80's, because said generals refused to implement a system that would prevent them from "hitting back".

He rightly insisted on Permissive Action Links for the US Strategic Air Command Minuteman missiles and bombs - so that they could only be armed and detonated by the the correct codes from the President or the rest of the chain of command. However, it turns out, that whilst McNamara was nominally in charge, that SAC decided to secretly order all the PAL codes to be set to eight zeros, so that there would not be any delays caused by communications problems during a nuclear war.

(From http://yorkshire-ranter.blogspot.com/2006/03/how-not-to-write-about-uk-nuclear.html)

What's hilarious is that there were extensive efforts to implement PAL securely; all sorts of tamper-proofing and obfuscation in the weapons to make it such that you'd have to have a fair bit of training to have any hope of setting one off. Roughly the equivalent of installing high-security deadbolts throughout your property, and leaving the key in the front door lock.

Re:Rumor had it...

[ducomputergeek]

On the minuteman ICBM's, one of the last launch procedures up until the late 1970's was to set the PAL's to 00000000.

I've spoken to former Silo men and they've confirmed at this was the case and the reasoning behind it was to make sure that people did not forget the codes (al la in the heat of the moment they freeze and forget) or to prevent some beurcractic mix up and SILO 123 got SILO 456's PAL codes, etc..

And apparently this was done on the quiet. Not that it was a big secret as much as they just didn't talk about it.

Pakistan DOES NOT have PALS

[d2_m_viant]

There's conflicting information about whether the Pakistani's have PALS. According to a recent article in the New York Times, the Pakistani's do not have it:

In the end, despite past federal aid to France and Russia on delicate points of nuclear security, the administration decided that it could not share the system with the Pakistanis because of legal restrictions.

And furthermore:

In addition, the Pakistanis were suspicious that any American-made technology in their warheads could include a secret "kill switch," enabling the Americans to turn off their weapons.

Likewise with Clinton:

While many nuclear experts in the federal government favored offering the PALS system because they considered Pakistan's arsenal among the world's most vulnerable to terrorist groups, some administration officials feared that sharing the technology would teach Pakistan too much about American weaponry. The same concern kept the Clinton administration from sharing the technology with China in the early 1990s.

Re:Quite sensible

[Duhavid]

If you haven't already, watch "Fail Safe".

Not Bicycle Locks.

[Anonymous Coward]

The actual keys (of which I have held one) are not bicycle lock keys, they merely share a similar outword appearence/size. The key is a heck of a lot more complex, as was the mechanism (and each key was unique). Furthermore, each weapon was guarded by groups of soldiers with very clear orders to shoot *anyone* who tried to gain access without the proper authorization. When tensions increased and aircraft were on alert (armed up on the flight line), the guards had orders to shoot at any aircraft attempting to take off with a live weapon, there was also a system of gates to prevent an aircraft from reaching the runway without the proper permits.

Part of the reason we didn't use PALS was that we were in closer proximity to the USSR, with less warning. Our government was (and still is) less resilient to a suprise attack than say the US. One suprise strike on London could eliminate our civilian chain of command instantly, the lack of PALS meant our forces could react to such events faster.

Fact is it worked, we also didn't have nuclear weapons going 'astray' back then either.