Most of the reaction to Jeremy Corbyn's interview with Andrew Marr yesterday has focused on his comments about Trident and his suggestion that the UK's nuclear submarines should be retained but without nuclear weapons on board.
As ridiculous as this may sound, it is in my opinion actually a perfectly arguable position. Submarines, with the ability to fire long-range weapons, are a valuable and sensible weapon for the country to retain. Nuclear weapons, with the ability to destroy the whole of mankind as we know it, are not.
Most other major developed nations do without such an apocalyptic arsenal and there's no reason why the UK shouldn't either. As even Tony Blair admitted in his autobiography: "On simple, pragmatic grounds there was a case either way [for keeping Trident]. The expense is huge, and the utility in a post-Cold War world is less in terms of deterrence, and non-existent in terms of military use. Spend the money on more helicopters, airlift, and anti-terror equipment? Not a daft notion," he wrote.
Blair ultimately decided to keep Trident, but it is a debate which could be winnable for Corbyn if Labour decided to make the case.
'Because key gateways have been capacity constrained, a lot of freighter services now terminate in mainland Europe'
However, the debate over the Falklands raised by Corbyn yesterday, is of a completely different order.
Whereas the debate over Trident is one based on hypothetical threats, the debate over the Falklands is not. The Argentinians have repeatedly threatened to capture the islands and there are military experts who believe the UK would be unable to defend them if they did. For the British people living on the islands, what leading UK politicians say about them really matters.
The debate also matters to millions of people living on mainland Britain. Asked yesterday about whether The UK should hold onto the islands, Corbyn told Marr that there "has to be a discussion about how we can bring about some reasonable accommodation with Argentina." Asked whether the Falklands Islanders would have a veto over the outcome of these discussions, Corbyn confirmed that they would not.
David Cameron, in his wildest fantasies could not have hoped for a more electorally advantageous statement to have come out of the Labour leader's mouth. If Corbyn had promised to start a debate about selling the white cliffs of Dover to the French, it could not have been any better for the Tories. In just a few catastrophic sentences, Corbyn surrendered not just the Falklands to the Argentinians, but the next general election to the Conservatives.
This may seem like an overreaction. There are many who think it is obvious that this tiny distant group of rocky islands off the coast of South America are not something the UK should fight to retain. They see them as a relic of British colonialism, as a kind of Hong Kong of the Atlantic.
Indeed this appears to be how Corbyn himself sees it, telling Marr that: "It seems to me ridiculous that in the 21st Century we could get into some enormous conflict with Argentina about the islands just off it."
But while Corbyn may see Britain's determination to cling onto the Falklands as "ridiculous", this fundamentally misunderstands the grip that the Falklands Islands and our defence of them has over our collective psyche.
Before the Falklands conflict, the then Conservative government was on the brink of collapse. Behind in the polls and led by an unpopular leader, the Tories were beginning to lose all hope of winning the upcoming general election.
When Thatcher successfully defended the islands, it not only fundamentally changed how the country saw her and her government, but it also changed how many British people saw their own country. For years the UK had seen itself as a declining military and economic power. The Falklands war changed that in a way that may be difficult for many of those who grew up in the era of the Iraq and Afghanistan wars, to grasp.
To understand the cultural significance of that conflict, you could do worse than watch the scene in Only Fools and Horses where Delboy's friend Jumbo returns to the UK and tries to persuade him to join him in America, explaining that "this country's finished. It's old, decrepit… the stench of defeat is everywhere."
Replying that "it's a British stench and I happen to be proud of it" an increasingly riled Del eventually turns on Jumbo and warns him to be "careful or you'll get what the Argies got, a good smack in the eye." Del ultimately decides to stay.
Filmed in 1986, the scene is revealing about how important the Falklands were and still are to how we see ourselves as a nation. The defence of the Falklands, although strategically and militarily largely insignificant, was massively psychologically significant to how British people understand our place in the world. Corbyn and his supporters may believe that feeling to be ridiculous. They may even be right. But it exists and it is powerful.
And it is a feeling which persists to this day. A poll conducted in 2012 found that the public would overwhelmingly support another war to defend the Falklands. According to the poll, a clear overall majority of 61% of voters would support war "at any costs" to defend the islands. Not at some cost, not at a reasonable amount of cost, but at any cost. This support was universal across all regions, classes and political parties.
By placing himself in opposition to that position, Corbyn not only set Labour on the opposite side of public opinion, but he has also handed his opponents all the ammunition they will ever need against him.
Jeremy Corbyn addressed the Fabian Society conference on Saturday
In recent months, the Conservatives have devoted all of their resources to trying to portray Jeremy Corbyn as a danger to the country. There is barely a press release they've put out which doesn't contain the statement that Corbyn and Labour are a "threat to national security." Until now that has been a laughable and hyperbolic charge. Today, it no longer looks quite as laughable.
Allowing part of your nation to pass into another nation's hands (against the inhabitants' will) is the definition of a threat to our national security. That Corbyn and his team don't seem to realise this, is more worrying that anything else he has said or done since he became leader last year.
On Saturday, the Labour leader addressed the Fabian Society conference. Following his speech, a panel of experts and commentators discussed what Labour need to do to in order to win the next election. Former Labour pollster Deborah Mattinson warned that the party are heading for a heavy defeat under Corbyn, due to the fact that the public simply don't trust him to govern. She was followed by columnist Owen Jones who, while much more supportive of Corbyn, warned that Labour must stop talking so much about foreign affairs and defence issues and concentrate instead on the sort of domestic issues which both party members and the public can rally around.
Within 24 hours the Labour leader was on the airwaves calling for unilateral disarmament and our negotiated surrender of the Falklands.
There is much to praise about Corbyn's leadership of the party. Because of his election, Labour party membership has almost doubled and he has achieved a number of significant victories, most notably on tax credits. But he has also allowed himself to be distracted by often obscure and factional issues, which even if voters have the slightest interest in them, they do not agree with Corbyn about.
Most of these are largely irrelevant to the outcome of the next general election, but the Falklands is an exception. By allowing his opponents to suggest that he would even consider surrendering part of our country to a foreign power, Corbyn has given up any real hope of ever becoming prime minister. In the battle to win back Downing Street, the war is over before it has even really begun.