As Japan's opposition leader, Yukio Hatoyama was a strong critic of what he called Tokyo's subservient position to Washington. But with his party now expected to take power, he is not likely to do anything to derail what has been Japan's most successful overseas alliance, analysts said.
Hatoyama, whose Democratic Party of Japan appeared to score an overwhelming victory in parliamentary elections on Sunday, has said Japan must distance itself from U.S. diplomatic policies and develop a more "independent" stance.
As opposition leader, he regularly criticized the staunchly pro-U.S. government for joining in refueling operations in the Indian Ocean in support of U.S. troops in Afghanistan - a mission he says he will halt - and questioned the role of the 50,000 American troops deployed throughout Japan under a post World War II mutual security pact.
But analysts say that if he becomes prime minister - as is expected now that his party and its allies are likely to outnumber the Liberal Democrats in the more powerful lower house of parliament - he will tone down his rhetoric while forging closer ties with Japan's Asian neighbors, including China.
"The Democrats would maintain the Japan-U.S. relationship pretty much as is to reassure the international community that there will be no drastic shift under the new government," said Tomoaki Iwai, a Nihon University political science professor.
He said Hatoyama is not expected to expend the political capital needed to push the issue - or risk alienating a key ally - because he will be too focused on trying to revive Japan's slumping economy, an issue which is of more concern to the nation.
"Diplomacy and security were not key campaign issues for voters, who were almost entirely focused on economy and other domestic issues," he said.
Giving a glimpse of his views to an American audience, Hatoyama wrote an op-ed piece for the New York Times last week.
"As a result of the failure of the Iraq war and the financial crisis, the era of U.S.-led globalism is coming to an end," Hatoyama wrote. But he also predicted that the United States, though declining in influence, "will remain the world's leading military and economic power for the next two to three decades."
He also said that he would not seek radical change in Japan's foreign policy, and the U.S.-Japan alliance would "continue to be the cornerstone of Japanese diplomatic policy."
"It was one thing for the opposition party to take opportunistic partisan shots at the (current Japanese) government for supporting the United States in the war on terror or paying for U.S. bases, but it is quite another to put the alliance at risk when in power," Michael Green, a White House Asia adviser during the George W. Bush administration, said in an interview posted by the Center for Strategic and International Studies think tank, where he is an analyst.
But Green said a victory for the Democrats could cause confusion in Washington and Tokyo "as the DPJ decides what it actually stands for in power."
Japanese analysts agreed that uncertainty is likely to remain for the time being because the Democrat's own lawmakers are unclear about what direction Japan should take on defense issues. Some DPJ conservatives want close military ties with the United States; another faction wants a more independent role for Japanese forces.
"National security is a major issue that the Democrats will have to sort out," said Takao Toshikawa, an independent political analyst. "It will be a major challenge for them to build a good relationship with the U.S. while reaching party consensus and gaining public support at the same time."