It was a speech Tsutomu Yamaguchi had waited 64 years to hear. Watching television at home in Hiroshima in April, one of Japan's most famous A-bomb survivors heard an American president call for the abolition of nuclear weapons.
"As... the only nuclear power to have used a nuclear weapon," Barack Obama said that day in Prague, "the United States has a moral responsibility to act." Mr Yamaguchi was elated. "I feel he is the only one we can now rely on the end these terrible weapons," he said.
Mr Yamaguchi's words carry more weight than most people's. In 1945 he was exposed to the only two atom bombs ever used in anger, both Hiroshima's and Nagasaki's. Now 93, Japan's only recognised double survivor has been dealing with the horrific consequences all his life. He has lost his son and wife in the past four years, both to cancer. And with only months to live himself, he is hoping that President Obama will visit his city before he too dies. "That would be very important to us, and to the world."
Political pressure at home and tight scheduling during Mr Obama's first visit to Japan on Friday and Saturday make the chances of a presidential trip to either city almost zero. Mr Obama arrives in Tokyo amid a growing firestorm over the relocation of a controversial US airbase in the southern Japanese island of Okinawa. He is still trying to establish a rapport with the country's new Democrat government, which is withdrawing its support for the US war in Afghanistan and has hinted at wanting more independence from Washington. For decades, Japan has been one of America's most dependable allies.
But Obama's unprecedented pledge in Prague, and his selection last month for the Nobel Peace Prize, have energised the pacifist movement in Japan, which for years feared it was losing the war against the spread of nuclear weapons. Hiroshima Mayor Tadatoshi Akiba called the speech a "clarion call" to the world. "President Obama knows that we are the majority standing on a solid moral foundation," he said, coining the phrase "Obamajority" to illustrate his point. Hiroshima and Nagasaki believe Mr Obama could be the first sitting US leader to see the devastation wrought by the bombs at first hand, despite the odds against it on this visit. President Gerald Ford probably came closest in 1974, when he was urged by his own advisers to deliver a speech on peace and reconciliation in Hiroshima – but the proposal was eventually overruled. George W. Bush called the proposal of a visit "an interesting idea", but predictably declined on his trips to Japan.
In the meantime, Mayors for Peace, a Nagasaki/Hiroshima global initiative campaigning for the elimination of nuclear weapons by 2020, claims to have signed up more than 3,000 cities worldwide, including London, Dublin and Cork. "Whatever happens during the Obama visit, we want to keep pouring our efforts into building public support and preparing the environment for abolition," Mr Akiba said this month.
Mr Obama is popular in Japan, whereas his predecessor, George Bush, was disliked for stretching the country's neutrality to breaking point in support of his "war on terror". Veteran campaigners have warned, however, that the road to a nuke-free world is not built by presidential speeches alone. Three decades ago, US President Jimmy Carter also called for disarmament before back-pedalling, peace activist Bruce Gagnon reminded a Hiroshima anti-nuclear conference in the summer. "When he ran for office he said, 'The arms race is a disgrace.' Then he built the biggest Trident nuclear submarine base in Georgia."
The two US bombs dropped on Hiroshima and Nagasaki on 6 August and 9 August 1945 killed an estimated 222,000 people. Both cities have watched America's post-9/11 plans to weaponise space and develop "useable" nuclear weapons with alarm. After the Prague speech, Mr Yamaguchi wrote to the US president offering his support and urging an end to what he calls the "weaponisation of cruelty".
"I asked him to carry on as president if four years are not enough,"he recalls. "Whatever happens, I'm just happy to have heard such comments from an American president before I die."