When did World War II end? The question is deceptively simple. If you are British, American, German, Japanese, French or Italian, then you undoubtedly would answer, without hesitation, in 1945.
Was Yalta a success or failure for Western leaders?
But if you happen to be Estonian, Latvian or Lithuanian, then you would answer as Mart Laar, twice a prime minister of Estonia does: "It ended only when the last Russian soldier left my country."
That puts the end of World War II as 1994.
In a series of programmes based on places that have shaped our world, I have been exploring with government leaders and politicians like Mart Laar, historians, economists, diplomats and others who took part, some of the momentous decisions agreed at the end of World War II which have shaped our world ever since.
From 4-11 February, 1945 the Big Three - Stalin, Churchill and Roosevelt - met at Yalta, a resort in the Crimea.
They put the seal on what became the division of Europe for almost 50 years. Yalta put the Iron in the Iron Curtain - the Cold in the Cold War.
What happened here settled the fate of tens of millions of people in Eastern Europe until the fall of Communism - though it did keep Greece, Turkey and Iran out of Stalin's reach.
But the historical questions about Yalta are still alive today.
Did the "Big Three" really meet as allies at Yalta?
Or - as the historian Gregor Dallas argues - were the Western leaders too readily seduced by Stalin, who just four years previously had been an ally of Hitler and who only ever acted in the interests of Soviet communism?
Above all, was Yalta the best deal the Western powers could get?
The USSR used the Red Army to control Eastern Europe for 40 years
President Roosevelt said as much - admitting that it was not a good deal but the best he could do.
Stalin's Red Army occupied much of the territory which later became the Communist sphere of influence, the Warsaw Pact, and short of World War III it is difficult to see what could have persuaded them to leave.
Some like historian Stephen Graubard, who as a young man was invited by Eleanor Roosevelt to attend FDR's fourth inauguration in 1944, argue that the widespread admiration for Soviet achievements during the war influenced Churchill and Stalin at Yalta.
He says: "We must remember what the Soviet Union had achieved between 1941 and 1945, and how that had affected the two great democracies of the world."
He argues that Yalta kept a stable peace in Europe, though at a heavy price.
Others - like former Prime Minister Laar - reject that argument:
"There was no peace in central and eastern Europe. Yes, there was no new world war, but actually there was a fight and no peace."
And Zbigniew Brzezinski, Jimmy Carter's Polish-born former national security adviser, accuses Roosevelt of naivete.
"Roosevelt's world view, his notions about the future, his perceptions of 'Uncle Joe' - all of that introduced a perspective which was far more accommodating than need be."
The collapse of the Berlin Wall heralded the end of Communism in Europe
Was it not naive of Roosevelt to believe Stalin's word when he signed up to a deal for a democratic Poland?
Why would Stalin grant a true democracy to the Poles when he had not done so for the Russians?
Dr Brzezinski agrees strongly with President George W Bush - speaking in Latvia this summer - when he said Yalta led to "one of the greatest wrongs of history".
And the new history which is emerging helps shed light on the whole period.
As Gregor Dallas says, it would be wonderful "if we could start reading the history of the Second World War and its aftermath in the light of what happened in eastern and central Europe and not just in the light of our own experiences."
But above all, the series - which includes the founding of the UN in San Francisco, of the UNHCR in Geneva and the key moment in the end of the European empires in Delhi in 1947 - demonstrates an important truth about the past.
It lives with us now.
The past, as the American writer William Faulkner argued, is not history.
It is not even past.
The series Six Places That Changed The World is broadcast every Monday until 19 September at 0900 BST on BBC Radio 4.