A former top aide to US President Barack Obama in a new book sharply criticizes Japan's leader after landmark 2009 elections, saying that even Vietnam was worried about his strategic thinking.

US officials have made no secret of their dislike of former prime minister Yukio Hatoyama, who urged a foreign policy more independent from the United States after his center-left party swept out long-ruling conservatives.

In a memoir, Jeff Bader, who served as Obama's adviser on East Asia until last year, said the White House had expected "at least some minor turbulence" after Japan's August 2009 election but soon found Hatoyama's policies outright "disturbing."

Bader voiced alarm about Hatoyama's call to build a regional forum that excluded the United States, comparing his "East Asia Community" to a proposal by Malaysia's firebrand former leader Mahathir Mohamad.

"The thought that America's closest ally in Asia should be pursuing a similar proposal was astonishing to the Obama administration," Bader, now a senior fellow at the Brookings Institution, wrote in his book "Obama and China's Rise."

Bader said that Vietnam voiced concern about Hatoyama's proposal during an Asian summit in Thailand, fearing that the Japanese would put China at the center of the bloc without the United States to balance it.

"The irony that Vietnam, of all countries, should have understood the strategic foolishness of such a proposal while America's strongest ally in the region did not was not lost on anyone," Bader wrote.

Bader, presenting his book Thursday, said that the United States learned of Vietnam's views from another chief of government. He did not name the leader, although Australia's then prime minister Kevin Rudd was presenting a rival proposal in Thailand that would have included the United States.

The United States stations some 47,000 troops in Japan under a security alliance forged after World War II.

Hatoyama resigned as prime minister in June 2010 after the United States refused to renegotiate a deal on moving a controversial airbase on Okinawa island, one of his campaign promises.

Relations between the allies have since improved after the United States led a major relief effort following Japan's devastating tsunami and current Prime Minister Yoshihiko Noda embraced a US-backed trans-Pacific trade pact.

But Bader warned that more trouble could arise, saying that the ruling Democratic Party of Japan has been "severely damaged" and the opposition Liberal Democratic Party "has not revived."

"It appears the United States will have to deal with a succession of weak, short-term cabinets there," he wrote.

In the book, Bader, who joined Obama's foreign policy team during his historic presidential campaign, gives fly-on-the-wall accounts of US decision-making on Asia from managing crises with North Korea to working with a rising China.

In one of the most dramatic accounts, Bader wrote of the tensions at the 2009 Copenhagen climate summit, where Obama famously barged into a room where Chinese Premier Wen Jiabao was meeting leaders of other key developing nations.

Bader said that Brazil's then president Luiz Inacio Lula da Silva responded to Obama's pitch with an "outburst about the arrogance of the West" and that senior Chinese official Xie Zhenhua became "red-faced with frustration."

According to the book, Obama told Lula curtly that he was "accepting most of what you've decided" and threatened to leave, saying: "You don't want to talk about it? Fine. I have plenty to do in Washington."

The Copenhagen summit led to wide disappointment by ending in vague promises. Bader called Denmark's leadership "mediocre" and credited Obama with saving the summit from a "complete breakdown."