President Barack Obama's "pivot" to China's neighborhood and the "reset" in relations with Russia have produced limited results for signature foreign policy initiatives designed to improved America's standing with its former Cold War rivals.

Obama has succeeded in increasing cooperation with Moscow on nuclear arms reduction and shoring up U.S. partnerships in Asia to counter expanding Chinese power. But on other questions crucial to U.S. interests, those countries have proved stubbornly unyielding.

From nuclear-armed North Korea to potentially nuclear-armed Iran, the Obama administration has won only lip-service pronouncements of agreement on the endgames, but little more. U.S. officials say Russia and China supported new penalties on Iran and fresh condemnations, but previous administrations had similar records.

China and Russia have blocked Obama's attempts to get the United Nations to take significant action against Syria's government and ignored U.S. warnings that they will end up on the wrong side of history.

The overtures have left Obama vulnerable to charges that he is being naive or too accommodating to both China and Russia.

Republican critics, including likely presidential nominee Mitt Romney, say the administration has gotten too little in return from Russia for concessions on missile defense and has not pressured China enough on currency and trade disputes that cost American jobs.

Attention turns to China this coming week when Secretary of State Hillary Rodham Clinton and Treasury Secretary Timothy Geithner attend strategic and economic talks in Beijing. Topics will include global economics, the violence in Sudan and maritime claims in Asia's seas.

But threatening to overshadow the discussions is the fate of a blind legal activist who, according to overseas activists, fled house arrest in his Chinese village and is under the protection of American officials. The escape by Chen Guangcheng, who has exposed forced abortions and sterilizations in villages as a result of China's one-child policy, underscores the fundamental differences between the two countries on human rights,

The U.S. and Chinese governments have not confirmed reports that he sought protection at the U.S. Embassy in Beijing.

Since Obama took office, China's booming economy has driven global growth while the U.S. has struggled to emerge from its worst economic downturn since the Great Depression.

Greater Chinese assertiveness has resulted in clashes with the U.S. over naval vessels in the Yellow Sea and American exporters trading with Taiwan; with Japan over fishing rights; and with Southeast Asian nations over claims to the resource-rich South China Sea.

Washington's chief complaint, however, has been Beijing's shielding of North Korea from harsher condemnation and punishment for its nuclear weapons program and provocations that nearly plunged the Korean peninsula into war two years ago.

Previous rounds of the U.S.-China dialogue have been hailed as productive and have included new educational and scientific exchanges. They haven't resolved points of contention over Taiwan, Tibet and human rights.

U.S. arms sales to Taiwan, which Beijing regards as a renegade province, still rankle China, and the irritation could grow worse with the emergence of a White House letter that raises the possibility the U.S. could sell new jet fighter aircraft to the island nation. Also, U.S. demands for greater respect for human rights and Tibetan culture have fallen on deaf ears.

With the Iraq war over and combat operations in Afghanistan ending over the next couple of years, the recalibrated focus on Asia directs American military might and diplomatic energy to booming markets such as China, India and Indonesia. More than half of the world's population lives in Asia, which is seen as the future center of the world economy.

U.S. policy calls for increased cooperation with Beijing, where possible, and checking Chinese power in cases where it threatens allies and neighbors.

To ease concerns posed by the threat of China-backed North Korea, the U.S. has strengthened military alliances with South Korea and Japan. By speaking out against Beijing's maritime claims, Washington improved ties with Southeast Asian nations fearful of an expansive and potentially belligerent Beijing.

U.S. relations with Vietnam and the Philippines in particular have benefited. Even reclusive Myanmar, long an international pariah protected by China's diplomatic sway, has initiated democratic and human rights reforms to improve its standing with the U.S. and the West. The U.S. has taken the lead on talks about a new regional trade pact that would exclude China.

"We dealt cooperatively, extensively and candidly with China's leaders, making clear our positive view of China's rise and its regional role," said Jeffrey Bader, Obama's top China adviser until June.

Speaking last month, he summed up the administration's China strategy this way: "To achieve limited but real success on global issues while pushing back when there was overreach."

The administration has had some success.

While China appeared to be on the offensive in 2010, it has eased somewhat its rhetoric and tried to repair relations with its neighbors. Having seen the U.S. make inroads in places such as Vietnam and Myanmar, the communist government has been more prudent even if its foreign policy objectives remain the same.

Yet there may be little Obama or any other U.S. president can do to eliminate the long-term strategic distrust between the countries. Washington fears that an anti-democratic regime bent on regional hegemony could one day replace it as the world's pre-eminent power, securing resources and favorable trade deals around the planet. Beijing sees its ascension threatened by U.S. economic and diplomatic alliances, particularly in Asia.

"At first glance, this heightened U.S. attention to the region has provoked consternation in Beijing," said Elizabeth Economy, director of Asia studies at the Council on Foreign Relations. But, she said, "a stronger United States presence in the region, in many respects, is a prerequisite for more effective cooperation with Beijing rather than an obstacle."

Obama also has worked to mend ties with the Kremlin. Relations plummeted during President George W. Bush's administration after Russia's 2008 war with Georgia and disagreements over missile defense and Iran.

A series of deals has helped reduce U.S. and Russian nuclear weapons, allow Moscow to enter the World Trade Organization and secure the Kremlin's cooperation in Afghanistan.

But the relationship has again become strained by renewed disputes over Obama's revised missile defense plans, Iran and Syria _ and Russia's own election fraud, coupled with incoming President Vladimir Putin's claim that internal unrest has been the result of American meddling.

"For a report card, I'd give the reset a solid `B,'" said Andrew Kuchins, Russia director at the Center for Strategic and International Studies. "It would have been a lot stronger a year ago. Now there are a lot of questions about the future."