It is Isil and Isil alone that has introduced this nauseating nihilism; and when I fantasise about my ideal solution for these people, I think of the end of Raiders of the Lost Ark, when the Nazi plunderers are physically vaporised before our eyes. I am sorry to sound vindictive, but that I think is what they deserve – and especially for their murder of the 82-year-old curator, Khalid al-Asaad.

Yeah, you may say, and who is going to avenge him? Who is going to play Yahweh? No one wants to take them on. Everyone is frit of Isil, you may say – and it seems that no one in any Western capital thinks Syria is worth the bones of a Pomeranian grenadier, as Bismarck put it, let alone of a British grenadier.

Well, I am not sure that this will do any more – not when we look at the tragedy unfurling in the Mediterranean, the hideous fate of the 71 Syrian refugees in that lorry in Austria, the awful scorching sufferings of the migrants trying to cross the Mediterranean.

A few years ago I went to Palmyra, and other places in Syria, and realised that it was a place of unbelievable cultural richness. We went to Aleppo and saw the ancient souk. We went to Apamea and saw the lustrous mosaics of hunting and wine-making and agriculture – reminding you that for centuries this place was the very heart of the Christian Roman empire.

I thought then that this country had a lush future. The food was delicious; the people were gentle and civilised and friendly. I imagined brochures for villas called Simply Syria; and trekking holidays and cycling holidays; perhaps even Club 18-30, in the racier parts of Damascus – shades of Beirut in the good old days. At the centre of it all was the magnetic pull of culture, and history, and the touristic notion that you could better yourself by exposure to one of the oldest civilisations in the world.

My optimism was founded entirely on my astonishment at the relics of the past – and if you think heritage is unimportant to tourism, look at the reasons people cite for coming to London, now the number one tourist destination on Earth. Yes, it’s the bars and the theatres and the nightlife – but when people are asked to explain the reasons, they always tick the box marked “history” or “heritage”. Syria has at least 6,000 years of it, and some of the world’s most famous and important sites. Until now.

The fate of all these relics is now either grim or uncertain, lost in the fog of war – as they are destroyed, like the souk of Aleppo; or sold by Isil to fund their operations. One day I hope and pray that this nightmare will end, that Isil will be defeated – and peace will return.

And then what? What future will there be for the country – with their economy in ruins, with the potential for tourism destroyed along with their cultural heritage? I perfectly accept that intervention has not often worked. It has been a disaster in Iraq; it has been a disaster in Libya. But can you honestly say that non-intervention in Syria has been a success? If we keep doing nothing about the nightmare in Syria, then frankly we must brace ourselves for an eternity of refugees, more people suffocating in airless cattle trucks at European motorway service stations, more people trying to climb the barbed wire that we are building around the European Union.

The number one political problem in Europe this summer is the movement of migrants, and there are many potential solutions. The Home Secretary has bravely proposed a fundamental reform to the EU – that we should disallow free movement of labour, unless the migrant worker has a clearly defined job to go to. I believe many people in this country would support such a reform, though the devil, as ever, would be in the detail. But we must also tackle the reasons why people flee their homes – and we cannot let Isil destroy sites that are not only emblems of our civilisation, but which offer hope for the Syrian economy. If the Syrians are deprived of their past, they will have no future.

It is not just that he has next to zero support among mainstream Labour MPs in the Commons; it doesn’t matter that he has rebelled against the party leadership ever since he has been in the House. Indeed, it doesn’t matter that he sometimes identifies the right problems – low pay, underinvestment in infrastructure, or whatever. It is his solutions that are so out of whack with reality.

This is a man whose policies are way, way to the Left even of the last Labour leader – Miliband – a man who in the end was resoundingly rejected by the electorate for being too Left-wing. Jeremy Corbyn is a bearded version of Ken Livingstone (I think they even go to the same tailor for their vests). He would take this country back to the 1970s, or perhaps even the 1790s. He believes in higher taxes and a bigger deficit, and kowtowing to the unions, and abandoning all attempts to introduce competition or academic rigour in schools – let alone reforming welfare.

Jeremy Corbyn takes 53% of support in new poll

He is a Sinn Fein-loving, monarchy-baiting, Israel-bashing believer in unilateral nuclear disarmament. It is nonsense to compare him to Michael Foot, who had been at least a Cabinet minister and before that a distinguished campaigner against the pre-war appeasers. This is a man who, for more than 30 years, has made a political career out of being explicitly and avowedly on the Spartist Left. He is a frondist, an inhabitant of the semi-Trot margin, an unrepentant lover of oppositionalism. Never in all his wildest dreams did he imagine that he might be leader of what has been – until this year – one of the major parties of government; and now he is having greatness thrust upon him.

How have the People’s party engineered this extraordinary horlicks? There are four groups of culprits. There is the Miliband regime, as mentioned, which not only came up with the deranged rules of the contest – by which, at one stage, the power to help choose the next Labour leader was handed to my old friend, the Conservative penseur Toby Young. Mili and co also shifted Labour so much to the Left that they managed to give a kind of spurious legitimacy to the Corbyn agenda. Miliband adopted wholesale the Livingstone playbook of state-enforced price freezes and rent controls and other attempts to buck the market.

There is a sense in which Corbyn is explicitly the heir of Miliband – and it is notable that Ed has kept a low profile lately, as if he realises the enormity of what he has done. The next group of culprits are all the New Labour old guard: Alastair Campbell, Mandelson, and above all Mr Tony himself – they have been cloth-eared in their response, hectoring Labour supporters who still haven’t forgiven them for the Iraq war; and as for Blair’s suggestion that Corbyn-backers “get a heart transplant”, it conjured an unfortunate image of our zillionaire former PM, jetting off to California for expensive organ-swapping procedures that are simply beyond the means of most people in this country.

The third set of villains is, of course, the other candidates, who have been so robotically dull that they have made Jeremy’s woolly ruminations seem positively electrifying. They are so torpid that it almost feels as if they want to lose. Come on, guys: where is the fire? Where are your plans to build a new Jerusalem? I cannot think of a single thing any of them has said – except to bash Corbyn, with the result that Corbyn is the story, Corbyn is the guy that everyone wants to see – and the loony Corbynmania grows, like a stock market bubble that will burst too late.

Which brings me to the group that bears final responsibility for what may – may, as I say – be about to happen: the armies of Labour rank and file who honestly seem to think that this might be the way forward. Yes, there really are a few hundred thousand people who seriously think that we should turn back the clock, take huge swathes of industry back into public ownership and massively expand the state.

The problem for Labour is that they do not represent the majority of people in this country. That is the real lesson of this campaign so far: that the mass of the Labour Party is totally out of touch with reality and common sense. How should we Tories react? Well, that is for another column; but in the meantime we watch with befuddlement and bewilderment that is turning all the time into a sense of exhilarating vindication: I told you they were loony.

The whole objective of expanding Heathrow was, in theory, to answer this basic question. So it is amazing to find that the Davies solution fails the very test he sets, failing to connect us abroad – and even at home.

Heathrow expansion has been explicitly sold to MPs as a way of helping links between London and the rest of the UK. But look at what Davies is forecasting. The number of UK connections goes not up but DOWN, from seven to four. I am not sure that they are aware of this in Scotland or Northern Ireland indeed in the Northern Powerhouse. Some British cities will be bitterly disappointed not to gain the promised links, and some will actually lose. And how many more long-haul destinations will we get? All of – wait for it – seven! By 2030.

There is absolutely no hope, on this plan, of catching up with our European rivals, let alone Dubai or any of the rapidly growing airports of Asia or America. You might wonder how this can be. How can we be so incompetent as to expand Heathrow, and produce such a pitiful increase in connectivity?

The answer is simple lack of capacity, combined with the constraints that Sir Howard has been obliged to place on his solution. In the hope of restricting the very serious increase in noise pollution, he has been forced to call for a partial ban on night flights. This would reduce Heathrow’s existing connections with Hong Kong, Singapore and China, and deter low-cost carriers whose business model needs early morning and late evening flights – and all this for a night flight “ban” that would actually increase the number of nocturnal noise victims by 33 per cent.

You might say the obvious solution to this capacity crunch is to build not just a third but a fourth runway. And yet this option, of course, is explicitly ruled out. A fourth runway would cause such an inferno of noise and pollution in west London that Sir Howard calls, preposterously, for a legal “ban” on the very idea.

^{What a new runway at Heathrow might look like (Graphic: PA)}

Now people may take these “bans” – on night flights and a fourth runway – with a pinch of salt. Heathrow Airport itself doesn’t accept them. It may be that these are more fingers-crossed promises, and that the whole exercise is fundamentally dishonest. But we must take Sir Howard at his word. In which case we would get a third runway that won’t perceptibly increase British links with the rest of the world, and that contrives to REDUCE domestic links, and with no possibility of further expansion.

This would be achieved at colossal and so far unacknowledged expense to the taxpayer. The bill for the third runway is currently put at £22.6 billion, including £5 billion for surface access. As Willie Walsh has been making clear, there is no way the airlines (mainly BA) are going to pay. The transport costs, says Transport for London, are nearer £15-20 billion. The whole bill is probably above £40 billion to the public purse. And the environmental damage is massive – another 250,000 people afflicted by noise pollution, taking the total to one million. No other society is contemplating such a step backwards.

Even on Sir Howard’s wildly over-optimistic figures, there would be another 28,000 people suffering noise of over 70 decibels. That is horrendously loud. Then there is the damage to air quality in London. This legal obstacle is so serious that the Davies report bizarrely proposes that we should build the runway – and then only use it if we can clean up the air.

As Sir Howard says, the traffic would be so bad that we would need a new congestion charge in west London; and all this misery for a solution that will be obsolete as soon as it is built.

If the Government wants to be long-termist it should go for the truly long- term solution, a four-runway hub, and the logical place is in the Thames estuary. The GDP growth unleashed would dwarf Heathrow, with 50 per cent more routes overall, double the number of domestic routes, to say nothing of the huge scope for much-needed housing and regeneration. That is what the Government should do – to stick with its principled stance, to keep its explicit manifesto promise.

This is the time to ignore the pleas of the largely foreign owners of Heathrow, and to back a solution that is better for hundreds of thousands of local people, better for the economy, and better for British business as well.