|Kennedy's speech at the Berlin wall remains an iconic part of world history [EPA]
In the world's often image-obsessed culture, one easily forgets how a handful of words, said by the right man, at the right time, in the right place, can change the world.
"Ich bin ein Berliner", "Mr Gorbachev, tear down this wall!" and "either you are with us, or you are with the terrorists".
These words are those of US presidents John F Kennedy in the Cold War city of Berlin of 1962; Ronald Reagan, in that same city in 1987; and George Bush, the previous president, before a joint session of US congress just two months after the September 11 attacks in 2001.
Now, as Barack Obama prepares for a major Cairo speech to repair relations with the Arab world, he might do well do look at presidential phrases which made world history and two of the reasons why they did so: The places they were delivered, and the challenges they laid down.
Kennedy's speech is recognised by many notable historians as the one of most famous moments of the Cold War.
The young, charismatic US leader travelled to the city, surveyed the barbed wire and no man's land of the Berlin Wall, and then was driven through crowds of tens of thousands of West Berliners chanting his name.
After he got to a public square (soon to be re-named in his honour), Kennedy delivered an eight-and-a-half minute oration that electrified not just Berliners, East and West, but the entire Western camp fighting Soviet-led communism.
And he made the place of his speech a major part of his argument.
"There are many people in the world who really don't understand, or say they don't, what is the great issue between the free world and the communist world. Let them come to Berlin," he told the crowd.
But it was, of course, his adaptation of the 2,000 year-old Roman boast "civis Romanus sum," which made history.
"All free men, wherever they may live, are citizens of Berlin, and, therefore, as a free man, I take pride in the words 'Ich bin ein Berliner [I am a Berliner]'."
Decades later, Ronald Reagan returned to Berlin in 1987 to deliver a speech at the city's Brandenburg Gate, protected by bulletproof glass from possible snipers positioned over the Wall in East Germany.
|Reagan's Berlin speech didn't reach Kennedy's heights but remained crucial [GALLO/GETTY]
His speech did not soar as high as Kennedy's, veering at times into technical jargon about arms-reduction talks with the Soviet Union.
But he carefully noted the changes (this was the era of "glasnost" and "perestroika") occurring in the Soviet bloc, the better to pry open the enemy's defences - if only rhetorically.
"We welcome change and openness; for we believe that freedom and security go together, that the advance of human liberty can only strengthen the cause of world peace," he said.
And then, standing before the wall that symbolised not just the Cold War but the Soviet system's fear its citizens would "vote with their feet" and flee to the West, he threw down the gauntlet:
"There is one sign the Soviets can make that would be unmistakable, that would advance dramatically the cause of freedom and peace," he said.
"General Secretary Gorbachev, if you seek peace, if you seek prosperity for the Soviet Union and Eastern Europe, if you seek liberalisation, come here to this gate.
"Mr Gorbachev, open this gate. Mr Gorbachev, tear down this wall!"
"Us and them"
The wall did not come down, Jericho-like, because of Reagan's words, of course.
|Bush's rhetoric after the 9/11 attacks was
perceived as alienating [Reuters]
But historians see the speech as a prophetic moment for the famously plain-spoken (and plain-thinking) president.
Time-warp to 2001, and a very different kind of speech.
It is just nine days after the attacks on the US of September 11, 2001, George Bush delivers a speech before congress, a speech intended to rally both and American and global audiences.
After reassuring his fellow citizens, and pledging to put all available resources into preventing more attacks, Bush says something Kennedy or Reagan might have:
"Freedom and fear are at war. The advance of human freedom, the great achievement of our time and the great hope of every time, now depends on us."
But it is his challenge to other nations that has now come to symbolise the "us-and-them" worldview of the Bush administration:
"And we will pursue nations that provide aid or safe haven to terrorism. Every nation in every region now has a decision to make: Either you are with us, or you are with the terrorists."
The problem is not so much that "one man's terrorist is another man's freedom fighter," as the saying goes.
In the very same speech he vowed to destroy the Taliban in short order, unless they delivered those who perpetrated the attacks.
Eight years later, the Taliban thrive in Afghanistan and Pakistan.
So what lessons can Obama draw from these speeches?
|Obama, often praised for his oratory skills,
faces great expectations in Cairo [AFP]
First - choose your place. Some in the US are suggesting Cairo, the leading intellectual Arab capital, does not send enough of a message.
Robert Malley and Huseein Aghan, two leading thinkers on Middle East affairs, suggest in this month's New York Review of Books a much more symbolic place:
"Why not consider a speech that will make even the most cynical pause - one that addresses the Palestinian refugees' concerns, is delivered to refugees, and given in a Palestinian refugee camp in Lebanon?" they write.
"President Obama, flanked by [Palestinian President Mahmoud] Abbas, surrounded by refugee leaders, speaking to a cheering crowd of thousands ... and, through them, to millions of Palestinians scattered across the globe," they said.
"The sight, powerful and stirring, could do more than any US plan to change the mood, minds, and emotions."
Second lesson: only throw down challenges you can realistically expect to come to fruition.
And make them challenges that try to open a door, as did Kennedy and Reagan, rather than threatening to slam one shut - as did George Bush.