The Guardian – “Risk of nuclear accidents is rising, says report on near-misses”
Most of what of what is in this is old news and a lot does indeed look recycled from Eric Schlosser’s excellent book “Command and Control“. For decades the military has wrestled with huge compromises in the design of nuclear weapons; many missiles were liquid fueled for a greater part of the Cold War making them inherently dangerous. Maintaining positive control of nuclear forces and making that survivable under attack has always been particularly hard to maintain. In fact I’m fairly certain that even today the British Trident fleet still does not have true positive control and a submarine commander could order an unauthorized launch. The US submarine fleet however is under positive control I believe. It was rumoured that during the 1970s the USSR looked into a Fail Deadly (Dead Hand) system of nuclear retaliation in response to US missiles’ improved accuracy and invulnerability thus presenting the USSR with the threat of a decapitating first strike.
If you want and keep nuclear weapons the fallibility of the design, the engineers, the operators and the command structure means that an accidental detonation is absolutely inevitable. The right combination of factors through accident, human error or even belligerence will result in such an explosion. It may take many more decades or even centuries for this to happen but it has to; already the proliferation of weapons and fissile material make this more and more inevitable. Ageing weapon systems, poor maintenance and the threat of terrorism add to these problems – not least the enormous former Soviet stockpile (here | here) which has provoked widespread concerns regarding condition, security and safety.
There has never been a weapon invented that is as potentially dangerous to its user than as to its adversary. However given the yield of modern weapons any criticality accident could range from injuring personnel to a catastrophic detonation. There is no safe threshold.