Dunkirk, and the Battle of Britain - the RAF's heroic struggle to shoot the Luftwaffe out of the skies above London and other British cities - were both turning points in the most convulsive global conflict ever seen.
If either had gone the other way, the world would today have been a very different place. Yes, Hitler's army may still have ground to a halt in the Russian snows and the stubbornness of Stalingrad.
And yes, Pearl Harbour may still have brought the US into the war. But if Britain had yielded to the assault from sea, land or sky, the whole of Europe would have fallen into Nazi hands - and whether either Russia or America would have ever then summoned the will to try to liberate it we shall never know.
A German victory in 1940 would have meant of course a very different future for post-war Europe.
There would have been none of the magnanimity shown to the defeated Germans after the war by the victorious Allies - determined as they were to learn the lessons of the settlement imposed on the Germans after World War I.
A defeated Britain (and a defeated Western Europe as a whole) would not have been encouraged to restore themselves as prosperous sovereign states (as Germany was, but would still no doubt be occupied territories administered in the last resort from Berlin. Vichy France provides an instructive model of how that would have played out.
Much of what we now know as western civilisation would have been replaced by the swastika and the jackboot.
Even those who like to focus on the debit side (and there is one) of what, in the postwar world, we sometimes call "the West" will surely agree that the escape from Nazi tyranny was critical to the maintenance of democracy and freedom for many, not least for us in New Zealand.
It is, I think, important for new generations to understand how close we came so recently, within the lifetimes of many still with us, to the loss of our liberties.
It is easy - at this distance in time and space from great events - to underrate their significance.
It is even easier not to pay tribute to the great courage and resilience of the British people and to the resolve they showed when France had fallen, and the British said (in the famous cartoon by Kiwi David Low), "Very well, alone."
It is fashionable to look today to other centres of economic power and cultural influence. And we quite rightly recognise the significance of our geographical location in the South Pacific and the contribution made to our national life by the Polynesian view of the world.
But it is salutary to be reminded of the debt we also owe to our British heritage, and of the pride and gratitude we are entitled to feel for the efforts made by the forbears of many of us to save us all from a wicked oppression.
We rightly honour the efforts and sacrifices made by our own Kiwi troops in the various theatres of that great conflict. Dunkirk provides us with the opportunity to recognise, not so much the military valour of the British, but their simple refusal to give up.
Bryan Gould is a former British MP and Waikato University Vice-Chancellor.
