Nuclear deterrence is not infallible: a conventional war can escalate into a global nuclear war
If the ultimate horror of a global nuclear war should ever come upon us, it is most likely that it would develop out of a conventional war.
Muttered threats
In the 1970s argument about nuclear weapons, supporters of deterrence frequently averred that “No rational man would use a nuclear weapon”. This was before the advent of Trump, who more than once suggested that he could attack another country and say he was not responsible. Confirmation of this story.
At the time of writing (May 2026) the leaders of Russia and of the USA have both given quiet hints that they might use nuclear weapons in the wars they are fighting, Putin in his illegal invasion of Ukraine, and Trump in his illegal attack on Iran. These muttered threats are a deviation from the classic case given for nuclear deterrence, which was that it was an elaborate and precise game of geopolitical chess played by experts whose minds were incredibly poverful. The threats from Putin and Trump are just “nuclear blackmail” (as in “This is what I could do if you don”t give me what I want”), but they do also give an indication of the way they are thinking, that nuclear weapons are something they could actually use.
Modern nuclear doctrine makes a distinction between “strategic” and “tactical” nuclear weapons. The latter are much smaller, about the size of the bomb that was used on Hiroshima in 1945, killing a mere 100,000 people, and some military theorists suggest that they could be used in much the same way as conventional bombs are used. This would be a very dangerous step, because it could escalate to the other side delivering more or bigger nuclear weapons, and then to a rapid escalation to an exchange of strategic nuclear weapons, that is, to an all-out, global nuclear war. The main worry of politicians engaging in a nuclear war is that the adversary might succeed in eliminating their nuclear forces. This is the “First Strike” doctrine, and it leads to hair-trigger instant responses and rapic escalation.
Faint hope
The only hope for mankind once nuclear exchanges start would be an act of de-escalation on the part of the side that was hit by the tactical weapon, so that they would be taking the hit philosophically, thinking “Well, these guys really do want to win, so we had better turn the other cheek and put our hands up and start talking about de-escalation”. This is a very faint possibility indeed. If politicians cannot see their way to de-escalation in times of peace, how can they possibly hope to de-escalate in times, when one tactical nuclear weapon has already been delivered and the generals are clamouring for the ICBM dogs to be let out?
This response is unlikely to the point of impossible. It is far more likely that they would respond with delivery of one or two of their own tactical weapons, starting a vicious spiral of escalation that would culminate in a global nuclear war, which would end human civilisation on this or any planet.
De-escalation now
It is therefore of the greatest importance that nuclear powers start talking together about these dangers right now, and set about reducing, rather than increasing, the number of nuclear weapons that they have in their possession.
Nuclear Deterrence is not infallible.
There have been at least eleven incidents where nuclear deterrence came perilously close to making the transition to nuclear war.
Although possession of nuclear weapons may raise the threshold at which a nuclear armed opponent might attack you, the threshold is not raised to impossible heights. It is possible, in a situation of international tension, with an ongoing proxy war, combined with a technical failure and a miscommunication, that the order to fire a nuclear weapon might be given.
In addition to these inherent vulnerabilities in the deterrence system, the integration of Artificial Intelligence (AI) in the deterrence system tends to make nuclear war even more likely.
Nuclear Deterrence is capable of failing.
Since the result of the failure of deterrence would be global nuclear war, which would mean the end of human civilisation, the only rational solution is that we must rid the Earth of these weapons of mass destruction, and reduce significantly the number and intensity of wars that are taking place.
This solution is possible, given the political will, and it is up to us, the people, to create that will, working with wise politicians to overcome the denial and intellectual laziness that operates in so many politicians and commentators.
Related pages
Next core statement: An all-out, Global Nuclear War would end human civilisation
Applying logic to the nuclear deterrence debate
Nuclear weapons can be eliminated
– Replace mutual paranoia with mutual trust
– Bring the military industrial complex under control
– Create and follow the pathway to Global Zero
A More Peaceful World 