Scandalous! Corbyn would not initiate or participate in a global nuclear holocaust.

Respect to Steve Bell http://www.theguardian.com/profile/stevebell

"I would not push the nuclear button" says Corbyn.

Murmurings ensue, from his own party, duly amplified by the Tory propaganda machine.

Let's unpack this nuclear weapons question.

There are two scenarios in which a British Prime Minister could fire our WMDs.

First, as a first strike on a state that has not already nuked us.
This would cause a retaliatory strike on us from that state and/or its allies. This would lead to further strikes from other nations, and we must assume that any nuclear strike would lead to all-out nuclear war, with firing of all of the 7,000 nukes which are primed to go immediately, followed by as many of the remaining 8,000 of the global nuclear stockpile launched as their owners could manage to deploy.

This would almost certainly put an end to the present phase of human civilisation. Don't believe it? Look at what 100 small nukes would do to the planet.

Second, a British PM could press the button in revenge for a nuclear attack on our soil.
This would lead to further attacks, again leading to the aforementioned all out global nuclear holocaust. This would only make recovery from the attack all the more difficult, because outside help would not be available.

Therefore in the actual situation, Corbyn's declaration is perfectly reasonable.
Hitting the button, either as a first or a second strike, only makes matters worse.

What about the cognitive aspect of the situation? Does Corbyn's reluctance to deploy weapons of mass destruction mean that the French or any other nuclear armed adversary could blackmail us?
"If you do not make your Prime Minister f*ck a pig in public, we will nuke you?"

Maybe. But our adversary cannot be 100% sure that in that situation, his Ministers will not in fact defenestrate Corbyn, and press the button themselves.

Nuclear games theory requires 100% certainty, which does not, of course, exist.

Since nuclear war would be infinitely destructive, and since there is a greater than zero chance of nuclear weapons leading to nuclear war, it follows that we must rid ourselves of these weapons. 

Even with Britain armed to the teeth with mega destructive capacity, deterrence is not safe.
All it takes is a geo-political clusterfuck for a global nuclear war to take place.

Therefore, Trident is militarily unusable. Its only use is as a symbol of the UK's pretensions to global power. The only reasonable use of that position is to lead the world to total nuclear disarmament.

This is not hippy stuff. .
Several major Cold Warriors, including Henry Kissinger, are calling for global abolition of nuclear weapons.

Deterrence is not safe.
We must abolish nuclear weapons.
Some country has to make the first move.
Why should that country not be Britain?

PS If you find this topic depressing, this will cheer you up:

PPS If you are pro-nuke, you have to answer two questions:
1) Does global nuclear war mean curtains for human civilisation?
2) Is nuclear deterrence incapable of failing? (if unsure, read this)