Isil are winning because they fight on terms nobody can - or will - match
The advice for all tourists to leave Tunisia was inevitable, and without a policy to defeat the Isil terrorists the costs will be catastrophic
The traffic suddenly slowed. Car horns were sounding up ahead. Then the crowds appeared, surging out of side streets, sweeping up the avenue and cheering. It seemed everybody was waving or was wrapped in a Tunisian flag. I asked the driver if there had been a football match, for the mood of the crowd was exuberant. "No, it is for the tourists," he replied. And then we passed a coach load of visitors.
There were locals of all ages pressing their open palms against the windows, a gesture of supplication and of welcome even though the tourists were going home, terrorised into departure by the rampage of a fundamentalist gunman the previous morning.
In a week crowded with poignant scenes, this was a stark portrait of loss. For the people of Sousse the constant departures - thousands would leave within a few days - signalled something more than a loss of income: they were also saying goodbye to a physical presence that linked them to shared values of tolerance and openness.
Everywhere I went I encountered kindness. In the medina, heart of the old town, the street vendors abandoned their normal rituals of commerce and simply shouted: 'Welcome.' A man steered me into his tea shop, thrust a glass of sweet tea into my hand and delivered a lengthy oration on the history of his city. "We have Jews here and Christians and Muslims. You have your origin and I have mine but we live together here."
I met a wonderful young woman, Imen Amamou, a nurse who is a devout Muslim, who went to the Imperial Marhaba Hotel to help the wounded the moment she heard about the attack. Imen wears a hijab which frames a broad happy face. "If you westerners leave us we will be left to face these extremists alone. Don't leave us," she told me.
So it was with real sadness that I heard the new travel advisory warnings tourists away from Tunisia. In the current climate it is probably inevitable, but the cost to Tunisia will be incalculable. And for the murdering zealots of IS it is the best news possible. They feed on the alienation wrought by poverty and they long to isolate Tunisia from the hated west.
Was there an alternative? Possibly, if the British and other western nations were willing to take up responsibility for securing the beach resorts. But foreign police would become targets for the extremists and a new quagmire would emerge.
There are no good resolutions to this unfolding catastrophe across the Middle East and North Africa. Isil are winning because they fight on terms nobody else can - or will - match. They are winning because the international system is too broken to respond coherently. Western foreign policy is often characterised by the far left as a vast conspiracy to re-conquer the old imperial world. This is nonsense. American policy under Obama is about staying clear of messy entanglements.
There is too little insight and courage, too much crisis management and hoping the local dictators and warlords and militia leaders, and their regional clients, will sort it out. But there is no resolution, only bloody stalemate. And millions are fleeing across international borders in search of sanctuary.
We are at sea without the political leadership on the UN Security Council to put international security before national ambitions. Democratic Tunisia is not yet a mess like Libya, Syria or Iraq. But only coherent and brave international leadership can save it.
Ten years a go last week the city I live in and love was terrorised. I was on my way to work when the news started to come over the car radio. Power outages in the city. Tube stations shutting. Then somebody mentioned the word bombs.
Thirty minutes later I was sitting on the back of a despatch bike racing to Tavistock Square where the number 30 bus had been blown up. Police cordons had already formed and were holding back the media and curious onlookers. But beyond the trees, thick with summer foliage, I could see the mangled remains of a red London bus.
The walls of the nearby British Medical Association were scarred with shrapnel and splattered with blood. My first thought was to call my family and warn them against coming to town or using the public transport system. With relief, I heard my wife answer the phone. They would be staying put for the day.
In the days that followed we listened to politicians and community leaders appeal for unity. For once, the emollient words had the ring of something like sincerity. More importantly they resonated with the people of London's many villages. The great question of those days was whether Britain could resist the temptations of atavism the bombers sought to unleash. It did. And how. This remains the most tolerant society I have ever lived in.
The struggles between extremism and reason, between the demands of security and the conditions for liberty are part of our everyday lives now. But they are faced here with remarkable common sense. If the bombers failed to achieve a victory it had as much to do with the will of reasonable people as it did the efforts of the security services.
Last week, I stood outside St Paul's Cathedral, that great symbol of an enduring city, and joined other Londoners for the minute's silence to remember the dead of 7/7. We were all there, all clinging to the human connection that separates us from the death dealers. I have lived in many cities but on Tuesday morning I was never prouder to be a Londoner.