NUCLEAR, BIOLOGICAL AND CHEMICAL WEAPONS
July 19, 2016: Valuable lessons were learned about nuclear weapons security after the Cold War ended in 1991. The most appreciated lesson was that it was much more difficult to actually use a stolen nuke than it was to steal one. This was learned quite by accident. By mutual agreement the United States and Russia destroyed most of their massive stockpile of nuclear weapons. This was done via disassembly and recycling of the nuclear material for power plant fuel. Both sides could inspect the process in some detail, to make sure all the weapons and their components were properly accounted for. In the course of doing this the U.S. discovered, or confirmed, many details of Russian nuclear weapons design and maintenance. It turned out that one reason the Russians were so eager to give up so many of their nukes was that these were the older ones that were much more expensive and troublesome to maintain. As the Americans were paying for some of the disassembly and providing markets for the recycled nuclear material it was a win-win for the Russians. The West had a lot more nuclear power plants than Russia and that’s where the market for this stuff was. As a bonus the West was now less anxious about anyone (well, mainly Islamic terrorists) stealing a Russian nuke. Word eventually got around that the risk and expense of stealing one was only the beginning of your very expensive problems in getting a workable nuke.
Old Russian (Soviet era) nuclear warheads were much more high maintenance than most, and after as little as six months without tinkering and replacement of worn parts, the bombs no longer work. That was something the Soviets kept secret. There's also a problem with the PAL (Permissive Action Links) codes. Without the PAL, you can't get the nuke to detonate. But more critical are the electronics and batteries, most of which are custom made, and the tritium booster material, which is always rapidly losing its unique ability to "boost" the initial reaction that makes the radioactive material explode.
Of course, if you could assemble a team of nuclear weapons engineers, you might be able to revive a "dead" nuke. It's this prospect that made counter-terrorism officials nervous. But when al Qaeda made a public appeal for scientists and engineers to join its ranks in 2006 nothing came of it. It was known that some Pakistani nuclear weapons experts had a favorable opinion of Islamic radicalism, but these fellows were closely watched and, because they are experts in their field, they were well aware, before the general public, that stealing Russian nukes was not practical, even if you had some Moslem nuclear weapons engineers on call. Bottom line; it's not impossible for Islamic terrorists to get their hands on a Russian nuke, that is in working order but it turned out to be so difficult to do and come away with a working weapon that no Islamic terrorist group was able to do it.
Nuclear weapons built by Pakistan are another matter. These also require regular maintenance but not to the extent that Cold War era Soviet models did. So far the Pakistanis have been capable of keeping their nukes secure. Part of that is the threat of other nuclear nations, like India, China, the United States and Israel retaliating if a functioning Pakistani nuke did get into Islamic terrorist hands.