One of these things is not like the others...
In a withering verdict on the actions of the Russian president in Ukraine, he told a woman who lost relatives in the Nazi Holocaust: 'And now Putin is doing just about the same as Hitler.'
The prince's extraordinary intervention is certain to cause international controversy.
It is likely to be seen as a criticism of the West for failing to confront Mr Putin over his seizure of Crimea. The annexation was the first by a major power in Europe since 1945.
Observers have compared the crisis in Ukraine with Hitler's takeovers of Czechoslovakia and Poland.
They have pointed to the similar use of disguised special forces to stir up tensions in disputed areas.
Comment: Is that the best that these 'observers' can come up with? Last time we checked, Poland and Czechoslovakia did not vote almost unilaterally to join Hitler's Germany. Neither did the Nazis annex them without the use of force. The ONLY similarity is that a region once drawn within the borders of one country is now drawn within another's, a similarity so nebulous as to be all but meaningless. Where have all the brain cells gone?
Charles, who is scheduled to meet Mr Putin at the D-Day commemorations in France on June 6, made his well-intentioned but unguarded comment during a visit to the Canadian Museum of Immigration in Halifax, Nova Scotia.
The prince is on a whistlestop tour of Canada with the Duchess of Cornwall - they have 41 engagements in just three and a half days.
On Monday, the pair paid a heartfelt tribute to Second World War veterans and their families over tea at the museum in Halifax's docks.
He was introduced to Marienne Ferguson, a museum volunteer who fled to Canada with her Jewish family when she was just 13.
The 78-year-old was born in what is now the Polish city of Gdansk, a key flashpoint in the Second World War.
A free city under the terms of the Versailles Treaty after the end of the Great War, it was seized by the Nazis on the first day of fighting in 1939.
Mrs Ferguson and her parents, two sisters and grandmother had managed to obtain permits to sail to Canada. But other members of her family failed to flee before the German army arrived.
Along with an estimated six hundred Jews from the city, they were sent to Nazi camps where they met their deaths.
Mrs Ferguson was given the chance to tell her incredible story to Charles as she showed him the museum's exhibits.
At the end of the visit, and surrounded by media, Charles made his off-the-cuff comment about the situation in Ukraine.
It was heard by several witnesses. Mother-of-three Mrs Ferguson said: 'I had finished showing him the exhibit and talked with him about my own family background and how I came to Canada.
'The prince then said "And now Putin is doing just about the same as Hitler".
'I must say that I agree with him and am sure a lot of people do. I was very surprised that he made the comment as I know they [members of the Royal Family] aren't meant to say these things but it was very heartfelt and honest.
Comment: It's too bad such a traumatic experience hasn't left Mrs. Ferguson with the ability to think critically and see REAL fascism (i.e., pathocracy) when it rears its ugly head: i.e., in Kiev and the West in general.
'I told the prince that while my family and I were lucky to get a permit to travel, many of my other relatives had permits but were unable to get out before war broke out on September 1. They were sent to the concentration camps and died.'
GAS DEAL OF THE CENTURY
Russia and China were last night frantically haggling over the 'deal of the century' on gas and investment.
Putin hopes to secure £240billion in guaranteed energy exports to China, making Russia far less dependent on Europe.
The two sides were edging towards a 'significant joint declaration', including military plans, although Russian sources said they had so far failed to agree on gas prices.
As relations between Russia and the West deteriorated rapidly, China issued a friendly statement on Ukraine to Moscow and the nations conducted a joint naval exercise.
Deputy Prime Minister Nick Clegg said the prince should be 'free to express himself'.
'I obviously can't comment on a conversation which was clearly a private a private conversation and I'm not going to start comparing one period of European history to another, but Prince Charles is able, I would have thought, to be free to express himself.
'I have never been of the view that if you are a member of the Royal family somehow you have to enter into some sort of Trappist vow of silence,' he told BBC Breakfast.
'I think he is entitled to his views, but don't know whether those were his views because I just don't think providing a running commentary on private conversations is useful to anybody.'
Former US secretary of state Hillary Clinton sparked uproar in Washington recently when she said very much the same as the heir to the throne. Lashing out at Moscow's plan to issue passports to ethnic Russians in Crimea, she said: 'Now, if this sounds familiar, it's what Hitler did back in the 1930s.'
What is unusual, however, is for a senior royal to express an opinion publicly on such a clearly sensitive diplomatic issue.
Charles is often criticised for meddling in domestic affairs of state as well as the infamous 'black spider' memos - so called because of his scrawling handwriting - that he is said to frequently write to ministers on issues close to his heart. But international issues, particularly one as sensitive as this, are considered taboo.
A spokesman for Clarence House said last night they would not comment on a private conversation.
...British analyses of history that always leave its own contribution pure and clean.
This is the country that played European powers off one another to bring about two world wars. And, lest we forget, manipulating Eastern European populations was central to Halford Mackinder's (the then incarnation of Zbigniew Brzezinski) plan to 'contain' (read: destroy) Russia.
What a revolting lot are the British elite.