Futenma airbase was built at the end of World War II
By Roland Buerk
BBC News, Tokyo
It seems a minor matter - whether or not to go ahead with a previously agreed plan to move an American military base on the island of Okinawa.
Hardly something, you might think, that could cause tension in the alliance between Japan and the United States, 50 years old this month and critical to the balance of power in Asia.
But Marine Corps Air Station Futenma has become the first test of Japan's intent to forge a new relationship with America and the world.
It is the key issue as Japan's Foreign Minister Katsuya Okada meets US Secretary of State Hillary Clinton in Hawaii on Tuesday.
The base is in the middle of a city and many local people have long been irritated by noise, as well as the fear of accidents and crime.
Okinawa is home to most of the 47,000 American troops based in Japan.
It was to ease the pressure on residents that the American and Japanese governments agreed in 2006 to move the base to a less populated area on the island's coast, despite concerns about the impact on the marine environment.
But everything was thrown into confusion last year.
The deal had been reached by the Liberal Democratic Party which dominated Japan for half a century.
In the elections in August the voters gave a landslide victory to the Democratic Party of Japan (DPJ) led by Prime Minister Yukio Hatoyama.
The new government believes Japan has been too subservient towards the United States in the past. It still values the alliance but wants it on more equal terms.
During the election campaign there was talk by the DPJ of moving the Futenma base off Okinawa, some even said it could be moved out of Japan altogether.
Adding to the complication is the fact that despite its commanding position in the lower house of the Diet, or parliament, the DPJ relies for its majority in the upper house on tiny coalition partners who oppose concessions to the US.
For the Americans the change of partner in Japan is clearly a big adjustment, after decades of dealing with the Liberal Democratic Party.
Japan's new government wants to put it on a more equal footing with the US
In the past Washington could view the relationship as a constant framework in East Asia within which to manage its response to the emergence of China and an unpredictable North Korea.
So far the Americans have been deeply reluctant to revisit the issue of the base.
The original negotiations took years and, going back to them, Washington says, would undermine broader security arrangements.
Back in October when he came to Tokyo, US Secretary of Defence Robert Gates said it would be "immensely complicated and counterproductive" to look at the issue again, and it was "time to move on".
The Americans had hoped the matter would be resolved by the time President Obama visited Japan in December.
Prime Minister Hatoyama has refused to be rushed, and his latest deadline is May.
writing in the New York Times former Assistant Secretary of Defence Joseph Nye described the Pentagon as "properly annoyed"
The spat with the Americans will have to be resolved because Japan's new government has wider ambitions.
The base is a key issue for Mrs Clinton's talks with Mr Okada
Yukio Hatoyama has been making efforts to get closer to China.
Last month he was even willing to break with usual Imperial Household Agency protocol to insist an audience with the Emperor was granted at short notice to visiting Chinese Vice President Xin Jinping.
Mr Hatoyama has spoken of creating an East Asian Community, even of a common currency along the lines of the Euro.
But for now the unanswered question of Marine Corps Air Station Futenma leaves him in a bind, between Washington and the expectations he has helped to build up at home.