The return of conservative Prime Minister Shinzo Abe in Japan has raised hopes in Washington for closer security ties, although US officials hope he keeps a lid on his more strident views.

Abe is a champion of revising the post-World War II pacifist constitution and may take shorter-term steps such as boosting defense spending and allowing greater military cooperation with the United States, Japan's treaty-bound ally.

His Liberal Democratic Party, which ruled almost continuously from 1955 until 2009, roared back Sunday with a crushing victory over the Democratic Party of Japan, which Abe accused of harming relations with the United States.

President Barack Obama's relations with DPJ-led Japanese governments have substantially improved after early friction. But Abe is seen as more supportive of US force deployments and has vowed no compromise with China in a worsening row over disputed islands.

Michael Green, the senior vice president for Asia at the Center for Strategic and International Studies, said that Abe's victory was a "net positive" for the United States and could in fact stabilize Japan-China ties.

"The view in Beijing is that their pressure tactics are working on Japan and I think it's important to disabuse them of that," Green said.

But Green, who served as the top Asia adviser to former president George W. Bush, feared that a new team in the second Obama administration could follow a "simplistic media picture" of a more hawkish Japan and potentially isolate Abe.

"If the administration decides it has to somehow counter Japan's shift to the right by brokering between Japan and China, it would not go well either in relations with Japan or China," he said.

But Green said that US priorities in Asia -- particularly the relationship between allies Japan and South Korea -- could face setbacks if Abe pursues a hard line over emotive history issues.

Abe, whose grandfather was arrested but not indicted as a World War II war criminal, has called in the past for rescinding Japan's apology to wartime sex slaves, known euphemistically as "comfort women."

But Abe, during his previous 2006-2007 premiership, worked to repair ties with China and South Korea and avoided politically charged visits to the Yasukuni shrine, which honors 2.5 million Japanese war dead including war criminals.

"There is a concern for US policymakers that his revisionist inclinations will spark new tensions in the region, but his statements of late have at least tried to temper those anxieties," said Weston Konishi, director of Asia-Pacific studies at the Institute for Foreign Policy Analysis.

"I think the hope is that he'll take a very responsible approach," he said.

Abe will likely face domestic pressure not to antagonize neighbors. Japanese business leaders have been alarmed by tensions and Abe governs in a coalition with New Komeito, a Buddhist party with pacifist views.

Konishi said there were "probably some circles in town that welcome" the return of familiar faces in the Liberal Democratic Party, but added that the Obama administration had developed a strong relationship with the Democrats.

Obama congratulated Abe and called the US-Japan alliance "the cornerstone of peace and prosperity in the Asia-Pacific." State Department spokeswoman Victoria Nuland said Washington has "worked with Japanese governments of both parties for decades" and looked forward to working with Abe.

James Schoff, a former Pentagon official who is a senior associate at the Carnegie Endowment for International Peace, said that Abe's effort on defense could be "a net benefit for everyone" if Japan complements the United States.

"But if the focus is more toward building up offensive capabilities vis-a-vis China, that's going to create probably more problems than it's worth from a US perspective," he said.

Yukio Hatoyama, the first prime minister following the DPJ's landmark 2009 win, resigned after clashing with the United States over the status of a controversial military base in Okinawa.

Relations improved after the round-the-clock US response to last year's tsunami and the Obama administration enjoyed strong ties with outgoing prime minister Yoshihiko Noda, who supported joining talks on a US-backed trade pact known as the Trans-Pacific Partnership.

The Liberal Democrats have been divided on the emerging deal. The party relies on support from farmers, many of whom adamantly oppose foreign competition.