Why didn't Britain's nuclear weapons deter Argentina from invading the Falklands?

Britains nuclear deterrent didnt work because the Argentines were aware that any first use of nuclear weapons by a NATO power would automatically demand a USSR response whether or not the USSR or their interests were directly targeted and that WW3 would ensue

The only nation which has ever used nuclear weapons against an enemy was the US, and it used them against Japan to end the war in a way that Japan would not forget...ever. Argentina's aggression did not rise to even a remote resemblance to that of Japan's against the US...

All of which leads to an intriguing answer and thought : Britain didn't use nuclear weapons against Argentina because Argentina was being silly and all it needed was a taste of old school Royal Marine stuff...In any event, Who in today's world would use nuclear arms against an enemy? Answer: Only in symmetrical warfare or terrorism.

All of which leads to a thought that crosses my mind from time to time which I immediately reject because I cannot point to or express any connecting impression or idea which supports it. In fact, it is easily ridiculed as silly tin hattery. But from time to time, the thought crops up and winks a wink at me over my whisky and water..wa

The thought: True terrorism which was seeking relevance for its cause would use a nuclear weapon. So why doesn't it.

Nuclear weapons are easy to build or easily obtained from a nuclear state.... That history might denounce this true terrorist surely will not stop one whose belief system is that destroying a non-believing enemy even if it means destruction to oneself is preferable to allowing the non-believing enemy to exist. So why hasn't one been used by the Oceania ubiquitous terrorism we are informed of 24/7/365 by almost every media outlet in the world? Yes, thousands die each year at the hands of insane people who blow themselves up...and that is the reason for my thought....Insane people are the ones doing it....and there is no want of insane people in this world ... but that is a far cry from a world wide terrorism....even if we can attach it to the Muslim faith because there are those Muslims de minimus in number, but made large by media exposure, who vociferously believe the insanity of killing innocents as a means to an end...

That no nuclear weapon has been used by those who profess to engage in terrorism as a means to their end--And what exactly is the end of the terrorism we see reported?-- suggests that there is a probability that the terrorists are kept in play by those who are desirous of ensuring anti-terrorist authoritarian control mechanisms which work exceedingly well against civilian populations and which could not be maintained outside an atmosphere of fear of terrorism.....And this leads to the thought that terrorism is sponsored by those who desire to maintain authoritarian control over populations, but cannot do so without some excuse. And the best excuse, bar none, is fight against a potentially nuclear armed existing world wide terrorist threat.

Corporations which control governments are the only group of people who seem to benefit from terrorist control measures. Corporate sponsored private or military anti-terrorist forces in nations whose resources they are exploiting work remarkably well at keeping the local population in line when it complains about the exploitation...Think of those nations which own the World Bank and the IMF and the other banking interests and their corporate clients and corrupt governments.....With information instant in today's world, there must be a boogy man out there necessitating all that anti-terrorist armed force out there...

Right?

Basically, anyone with nukes has to stop and think, "how will history judge us?" if they were to use those nukes for anything less than stopping a major threat to their very existence. I can't believe your question is serious -- there is no way that Britain would think of using nukes to maintain their claim to some remote islands. They had sufficient conventional power (armed forces) to do the job.

The US has never quite shaken accusations that we were too eager to make a nuclear attack on Imperial Japan in the closing months of WWII, and that has helped stay our hand when hotheads were arguing for the use of nukes against the USSR, in Korea, in Vietnam, and probably elsewhere. You can argue all you want that (in hindsight) Japan was about to collapse anyway, from our submarine blockade and round-the-clock bombing, but to our leaders at the time, it genuinely looked like invading them to wrap up the war would be terribly costly.

I could see making a preemptive nuclear attack on someone nuclear-armed like Pakistan, if they were to continue sliding into a radical Islamist culture. They would just be too dangerous to have around with such weapons (including handing them over to the Taliban). Likewise, radical nutjob North Korea, if it builds up a large enough nuclear arsenal to genuinely threaten South Korea or Japan, would have to be taken out preemptively. Of course, their own use of even a single nuke against us or our friends should result in their obliteration. Let's hope these scenarios don't come to pass, but they might.

The Argentians were not deterred by the fact that Britain possessed nuclear weapons, because they believed that the British would not plausibly use nuclear weapons against them.

The Argentians apparently believed their invasion could succeed, because the British lacked both the willpower and the capability to evict them, so they would just get away with it.

This highlights the fundamental issue with nuclear weapons. Not very useful in anything except a total/suicide/M.A.D. war, or as a terrorist device.

The signatory states of the Non-Proliferation Treaty(NPT) with nuclear weapons (and the UK is one of these) have made it clear that they will not use nuclear weapons against signatory states without nuclear weapons except in response to a nuclear attack, or a conventional attack in alliance with a Nuclear Weapons State.

So unless the UK wanted to throw the NPT into the dustbin and risk nuclear proliferation, they could not use nuclear weapons against Argentina.

Doesn't the quote in the question answer it? Argentina, as a non-nuclear state, was not threatening "nuclear blackmail". The UK's rapid recapture of the Falklands by conventional means demonstrates (with the benefit of hindsight) that Argentina's invasion was not an "[act] of aggression against our vital interests that [could not] be countered by other means."