President Obama pauses while speaking to the media during a news conference at the White House a day after Democrats lost the Senate majority. (Evan Vucci/AP)

A Republican romp in U.S. midterm elections that was built in part on American anxiety about an increasingly dangerous world prompted concerns from overseas Wednesday that President Obama’s global role will only be further diminished.

With little prospect of an end to Washington gridlock on major domestic issues, Obama will have no shortage of foreign crises to turn to, including Russian advances in Ukraine, the disintegrating order in the Middle East and the threat of a spreading Ebola virus.

But from London to Tokyo, observers said the bruising defeats suffered by Obama’s Democratic allies will probably leave him with less clout to navigate global troubles — and could add to a leadership void that Republicans seized on to help gain advantage with voters.

“Obama has become the incredible shrinking president,” said Jeff Kingston, director of Asian studies at Temple University’s campus in Tokyo. “He’s very much weakened by the midterm results, and that’s going to diminish him in his foreign policy. Leaders in Asia will now view him as a lame duck.”

In Europe, where Obama remains considerably more popular than he is at home, leaders long ago gave up on the idea that he could fundamentally reorient America’s global role. But Tuesday’s defeat confirmed that there will continue to be a vacuum in the final two years of what many Europeans once hoped would be a transformational presidency.

“I don’t think Europeans were expecting much in terms of U.S. leadership over the next two years, and this will reinforce their beliefs,” said Mujtaba Rahman, Europe director for the Eurasia Group, a global consulting firm.

The election results also could embolden American adversaries to further prod the limits of U.S. power.

“If they see that the U.S. is tied hand and foot at home because of domestic constraints, those in Moscow, Beijing or at Islamic State headquarters might be thinking America is a house divided against itself, and a house divided against itself is weak,” said Michael Cox, co-director of LSE Ideas, a London-based think tank. “Given the complexity of the challenges facing the West, this is about the worst time possible for a divided America and a weak Europe.”

In Russia, which has been locked in an intense battle with the West over Ukraine, lawmakers greeted the Democratic defeat with glee and seized on it as a moment to attack Obama.

“I believe this ‘Democratic failure’ is a personal defeat for Obama, the result of his very low ratings, a sharp deterioration of his image as he has evolved from the president of hope to the president of disappointment,” Alexei Pushkov, head of the foreign affairs committee in Russia’s lower house of parliament, told the state-owned Tass news ­agency.

But he tempered his comments with caution about the consequences for Russia. Republicans are likely to take a harder line against Russia than has Obama, and the Republican takeover of the Senate will result in an “unfavorable vector, Pushkov said.

While Obama and congressional Republicans have broadly agreed on the need to adopt a tough line on Russia, a potential clash looms over the handling of another key antagonist: Iran.

The GOP gained control of the Senate Tuesday night, taking hold of the legislative agenda in that chamber. Here are three of the policies Republicans are likely to tackle as they take the reins in January 2015. (Julie Percha/The Washington Post)

Diplomats are engaged in high-stakes negotiations toward a possible deal that would reduce and place controls on Iran’s ­uranium-enrichment capacity in exchange for a loosening of Western sanctions. The White House can suspend U.S. sanctions without congressional approval but would need a vote to lift them permanently — an unlikely scenario at a time when Republicans have been urging an even tougher crackdown on Iran’s economy.

In a commentary by Iran’s state-run Press TV, the election was interpreted as a backlash against Obama’s inability to adapt U.S. policies to “today’s uncontrollable, deeply polarized world.”

“The rest of the world has, with a heavy heart and agony of mind, reached the conclusion that his power is indeed fading,” the commentary said.

Beyond trying to manage crises, among the few foreign policy areas where Obama might expect to make progress in his final two years, analysts said, is trade.

A Republican-controlled Congress is expected to be more supportive of the Trans-Pacific Partnership, a free-trade deal linking 12 countries.

Politicians in Tokyo blame Washington for the slow progress toward a trade deal because Obama does not have the “fast track” authority from Congress needed to push it through.

Senate Democratic leader Harry M. Reid (Nev.) had refused to allow a bill giving Obama such authority to come up for a vote. But Sen. Mitch McConnell (Ky.), the Republican now in line to run the upper chamber, is expected to view the issue more favorably.

“This could put the life back in TPP,” Kingston said. “There are better than even chances that Obama will be granted fast-track authority to negotiate a deal without congressional tweaking, and that is crucial to get other countries to put their best offers on the table.”

Republicans, backed by big business, have a history of being much more supportive of free-trade deals. If a Republican Senate gives Obama the authority to strike a multilateral TPP agreement, then the ball would be back in Japan’s court.

TPP is partly aimed at binding together the 12 members — including Japan, Chile, Canada, Mexico and New Zealand — and acting as a counterweight to rising Chinese power.

A similar trade deal being hammered out between Washington and Europe also could get a boost from Tuesday’s results, although that agreement is far less likely to be inked in the next two years. Rahman said that even if politicians in Washington can agree on terms, Europe remains divided.

Analysts said a Republican-controlled Senate could have a negative effect on relations with China, although they warned that it was too soon to tell.

“Obama will face more criticism of his policies on China, and that could push him to a tougher foreign policy,” said Zhu Feng, an international relations professor at Peking University. “A lot of friction already exists between the U.S. and China, and it might only grow worse.”

Indeed, there is growing concern in Congress that China is not playing by the rules and is enjoying unfair trade advantages, said Bonnie Glaser, a China expert at the Center for Strategic and International Studies. “There’s a sense that the U.S. should be tougher on China,” she said. “That comes from both sides, but Republicans are just more willing to use it against the president as a tactical move to say Obama is being too soft on China.”

Fifield reported from Tokyo. Carol Morello in Paris, Michael Birnbaum in Moscow, William Wan and Xu Jing in Beijing, Karla Adam in London, Yuki Oda in Tokyo and Yoonjung Seo in Seoul contributed to this report.