It is a great privilege to be at Bradfield, 57 years after I left. I want particularly to address the younger generation, but as young adults, not as schoolboys and girls and sombrely, not emotively.

Exactly 100 years ago to the hour, guns fell silent as a result of the Armistice which ended the dreadful slaughter of the Great War; 1.1 million British, 1.6 million French and 2.5 million Germans died, mostly young men.

Wars are not started by the soldiers who die in them. They are the result of political and diplomatic failure, neglect, miscalculation, bragadoccio or poor statecraft and leadership. Some of you may aspire to be political leaders so you must understand this particularly if, as you may, you ever have to take the awful decision to commit your fellow citizens to fight and die. I am a serviceman who is lucky enough still to be here to enjoy all the good things of life, although some of my friends and contemporaries are not, in part because of these failures of diplomacy and statecraft.

I was recently in Sicily, close to the ancient hilltop town of Agira, in one of the war cemeteries. This one shelters the remains of 500 Canadians, many of them as young as 17, who took part in the invasion of Sicily 75 years ago. They were mainly there voluntarily, combating a great and threatening evil. If they had been put in this position by the leaders of the nations, that was not their fault, nor does it in the least diminish the enormity, selflessness and generosity of their personal sacrifice, or the respect in which we should hold them and their example which you may need to emulate one day.

The question these cemeteries raise is not just “Do we remember them?” rather it is “How do we best honour the sacrifice of thousands of people in the last century or so, in a world which remains, as for millennia, torn by evil, argument and conflict?”

In WWI, because of the loss of so many soldiers, tens of thousands of civilian workers were recruited to a Labour Force, to provide battlefield labour and logistic workforces. They carried forward food, ammunition and stores, dug trenches, built and maintained roads and railways, cleared live ordnance, tended the wounded and exhumed bodies for re-burial in those cemeteries. 95,000 of them came from mainland China, of whom at least 20,000 died, many miles from their own homes. Six hundred native South Africans died when the ship carrying them North was sunk in a collision off the Isle of Wight. Most of these people have no memorial. Even their medals bore their numbers, not their names. Happily, this shameful failure is now being rectified.

In WWII as well, tens of thousands of men and women, military and civilians, once again came to our aid in the most dangerous moment in our history to date. My own mother drove ambulances during the blitz. People came to fight from the USA, before they entered the war, from Poland, Denmark, Norway and elsewhere. Many came because they felt the need to do something about the evil they saw.

And in both World Wars nearly 50,000 civilian merchant seamen died, bringing vital food and supplies to this country, a casualty rate proportionately higher than in any of the Armed Services. Most of these sailors have no grave but the sea; nothing tangible for their families and descendants, although they at least have memorials. Less so the merchant seamen of other nations who also died bringing us food and raw materials. What can we learn from all this?

It is right that we should honour the memory of our soldiers, sailors and airmen. We would have lost our freedom and way of life without their courage and sacrifice. But we must also all recognise our great debt to so many other people in our own country, and elsewhere, for our survival, and for our free, comfortable, relatively safe and prosperous lives today.

No natural law guarantees us these things, denied to many people across the globe. Historically they are an aberration. They have to be earned and, when necessary, defended. And they must be shared. Many of those who came here from far away were under no obligation other than their personal sense of justice, rightness, generosity, and a commitment to decency and principle, to die for us, people in a foreign country they did not know. This gives us an inescapable obligation today to assist their descendants when necessary.

But are we today clear what we stand for? Have we the same commitment, courage and generosity?

Why do I ask? Because the world remains a dangerous and divided place. There are constant threats to us and to people round the world. And as Edmund Burke said “all that is necessary for the triumph of evil is that good men do nothing.”

Sooner than you think, the world and its future will be yours to shape and make. Every generation has its particular challenges. I don’t know what your challenges will be. They are likely to be as difficult, and dangerous, as in previous generations. But the world is a single community – we cannot escape responsibility for what happens or for failing to prevent it. Nor can we ignore our obligation to other people elsewhere. Inaction is a decision to allow evil to succeed; it has moral consequences.

Armed conflict is a very terrible thing. Tragically that has never prevented it. Sometimes it may even be right to go to war rather than to let evil have free rein. But, as the great military thinker Clausewitz suggested, the purpose of war is to achieve, when diplomacy has failed, a better situation than existed previously. This means that the sole moral aim of war is a good, just, fair, and durable peace for all. Without this, nobody wins. I don’t think the 1918 Armistice met these criteria; it certainly failed to keep the peace. This is something from which we must learn. War, if it should occur, must be the precursor to peace and rebuilding, and never an end in itself. We have far too often forgotten this.

This, then, is the lesson of the Armistice. Managing it all demands from you the ability and the courage to stand up for the good and resist the bad, whatever that may take. It demands intellectual honesty, compassion, generosity, humility. It even demands a sense of humour. Most of all it demands the ability to recognise what makes for good long-term relations between people and nations. These are things not, I am afraid, always apparent in contemporary politics. On this Centenary, we cannot do better than to remember what past generations have done for us, note where they failed, and learn from and draw on their experience to make the world a better place.

This will be your task when you enter the adult world. Good luck to you all and may God support you.