TOKYO — A Japanese diplomat, asked what effect the election of the Democratic Party of Japan and a new prime minister, Yukio Hatoyama, would have on Japan's alliance with the United States, was succinct: "Nobody knows." An American official, asked the same question, sighed: "We don't know yet."

The Japan-U.S. alliance, considered until now to have been vital to the best interests of both nations, has entered a time of great uncertainty, for two reasons:

• The election of the DPJ to the control of the national Diet and the choice of Hatoyama, who is scheduled to take office on Wednesday, has brought to power a band of inexperienced politicians led by a prime minister who has issued vague, meandering and apparently contradictory statements on foreign policy.

• The absence of an articulated policy toward Japan by President Obama other than platitudes, the dispatch of Secretary of State Hillary Clinton to bring greetings but little of substance to Japan last winter, and the appointment of an ambassador, John Roos, whose only credential is political fund-raiser.

Hatoyama wrote an opinion article in the Japanese monthly journal Voice that was translated into English and excerpted in The New York Times, startling some Americans with its anti-American tone. Hatoyama, asserting that his statements had been taken out of context, had the entire essay translated. The anti-U.S. tone remained but was diluted by windy passages lauding the philosophy of Count Richard Coudenhove-Kalergi.

Coudenhove-Kalergi was an Austrian aristocrat whose mother, Mitsuko Aoyama, was Japanese and who was best known before World War II for his advocacy of European integration. He fled from Nazi Germany to the United States during the war and is said to be the model for the anti-Nazi activist Victor Lazlo in the movie "Casablanca."

Hatoyama, saying the influence of the United States is declining, wondered: "How should Japan maintain its political and economic independence and protect its national interest when caught between the United States, which is fighting to retain its position as the world's dominant power, and China, which is seeking to become one?" He suggested that an integrated East Asian community would be in Japan's interest.

A close Hatoyama adviser, Jitsuro Terashima, who heads a Tokyo think tank, appears to have carried that further. Writing in the current issue of the influential monthly magazine Bungei Shinju, he said: "Since Japan is under the protection of the U.S. nuclear umbrella, the Japanese government is not able to form its own foreign policy." Whether Terashima advocated having Japan acquire its own nuclear weapons, he did not say.

"It is unusual that Japan still allows the U.S. to keep forces in Japan more than 60 years after the end of the war," Terashima wrote. "Japan should go back to common sense and not to let a foreign force stay in this sovereign nation." He proposed that the United States shift its forces to Guam and Hawai'i.

Ambassador Roos, who has had little experience in Japan, or in diplomacy, or coordinating the work of other agencies with officials in his embassy, or dealing with the bureaucracy back in Washington, arrived here last month.

Roos has met with Hatoyama and the prospective foreign minister, Katsuya Okada, another advocate of less reliance on the Japan-U.S. alliance. Okada has been quoted here as saying: "It will be the age of Asia and in that context it is important for Japan to have its own stance, to play its role in the region."