Questions remain over Afghanistan campaign
It was a low-key ceremony at Camp Bastion. But it was a powerful and poignant moment, especially for the British.
After 13 years, it was the end for them of a grim and gruelling campaign, especially in the last eight years when they took on the Taliban in the key southern province of Helmand.
For the Nato-led combat mission as a whole, it's not quite the end yet. But it soon will be.
And that'll be a significant moment for all the contributing countries, and for the Afghans.
Who knows what the thoughts were of the final couple of hundred or so British troops as they left Helmand for the last time?
The official mantra was that they HAD made a difference, and that the 453 who were killed during the mission and the many hundreds left with grievous injuries, hadn't died or suffered in vain.
No-one was doubting the valour of those who had served.
There ARE new roads, new schools, a new Afghan army, and the chance to embed a more democratic and prosperous future.
But the costs have been huge. And, still, there are no guarantees.
And there were mistakes: A failed poppy-eradication campaign, the Taliban confronted but as yet undefeated, and huge questions over the effort against just as crucial an enemy, the spectre of corruption.
Shifting strategic goals seemed to confuse the public in the West and in the region, undermining support, and adding to the costs, in lives and money.
It started as a mission to punish al-Qaeda, and ended as a full-blown effort to build a nation in the face of a full-blown Taliban insurgency.
Much time and effort was wasted.
Perhaps only in the last few years, with President Obama's surge and a renewed effort to train Afghan forces, did what was in many ways an extraordinary Nato-led coalition receive anything like the resources it needed.
The outcome of it all though - and therefore the verdict - must remain uncertain.
Much will depend on how the Afghan authorities and security forces perform from now on, and what continuing support - but not combat forces - the outside world provides.
There may be reason for hope and foreboding. Iraq right now is a warning.
Would it have been better if Washington and its allies had left as soon as the Taliban and al-Qaeda had been put to flight?
Or, if they had done more sooner, would that have forestalled a Taliban resurgence?
The debate will continue to rage. As the British flag was lowered for the last time at Camp Bastion, what is the balance sheet for Britain?
At home, the armed forces may be held in the highest esteem for their exploits, but the doubts that any of it has enhanced British security are widespread.
Britain has a battle-hardened military that's learnt painful lessons, but it's a war-weary nation.
Questions for the West
And did it take on too much in Afghanistan? If so, whose fault was that? Over-ambitious politicians or over-confident generals?
And what lasting impact will Afghanistan - and the war weariness undoubtedly now felt in Britain - have on the country's ability and appetite to be a major global player, and to continue to be America's "first ally"?
These are also questions for the West as a whole, including the US.
How will the strains of Iraq and Afghanistan, and the scars of those campaigns, affect their willingness and ability to intervene in future crises, and to endure the kinds of conflicts that may not end in clear-cut military victories?
Whatever Washington and London mean exactly by "no boots on the ground" in confronting Islamic State - and there is plenty of room for doubt there - part of their meaning is clearly that it won't be like Iraq last time or Afghanistan.
For better or worse, that is part of the legacy of the huge resources and resolve expended in both.