By HELENE COOPER

WASHINGTON - A fundamental tenet of foreign policy says that nations will seldom voluntarily act against what they have determined to be their own national interest. Somebody needs to tell that to the United States when it comes to China, many foreign policy experts say.

A key part of America’s relationship with China turns on an impossible conundrum: How to get Beijing to make moves that its leaders don’t think are good for their country? From economics to climate change to currency to Iran and culminating with North Korea’s shelling of South Korean territory last month, America has sought to push, prod and cajole China, to little or no avail. Beijing has resisted letting its currency rise because it depends on the cheap yuan to drive its export-heavy economy.

China has balked at sanctions to rein in Iran’s nuclear ambitions because it needs access to Iran’s oil . Beijing doesn’t want to curb carbon emissions because its ability to lift hundreds of millions of people into the middle class is linked to its increased use of energy.

And, finally, Beijing has recoiled at reining in its unruly neighbor to the east, as the Obama administration implored it to do last month, because it doesn’t want to destabilize North Korea to an extent that could lead to the government’s collapse and reunification with South Korea. “Basically, the U.S. wants China to do what the U.S. wants it to do,” said Rodger Baker, vice president for strategic intelligence at Stratfor, a geopolitical risk analysis company.

“We want to make sure that the world stays as the United States would like to see the world. Which means making China subservient to us in some cases.

“In the case of North Korea, the Chinese see it as the United States pushing its policy on China and not allowing the Chinese to make their own policy, while removing from China one of the tools that it has decided it needs for its own interests.”

In this case, that tool would be a divided Korea, with a North Korea that is beholden to and wholly dependent on China serving as a buffer against America. But North Korea’s deadly attack and the recent disclosure of a just-completed centrifuge plant that could enable the north to add to its arsenal of nuclear weapons led the Obama administration to ask China to rein in Pyongyang.

So far, China is not cooperating, and will not cooperate, on either North Korea or the host of other issues, some experts say, until the United States changes its tactics and how it views Beijing. “We’re still struggling with a post-unilateralist hangover,” said David Rothkopf, author of “Running the World: The Inside Story of the National Security Council and the Architects of American Power.” That hangover, he says, leads Americans to believe “that we’re the sole remaining superpower and the objective of our foreign policy is to get people to go along with that.

To fall into step with our world view. But the reality is, that’s not what the future holds.” Rather, Mr. Rothkopf argues, the United States is heading into a future in which countries like China are not reliant on or easily influenced by the United States, and so are pursuing their own national interests. Some Obama administration officials say that they are aware of this shift, and have begun to adapt their strategy toward China .

Mr. Obama’s recent trip to India, in which he endorsed India’s bid for a permanent seat on the United Nations Security Council, should be viewed not only in the context of America and India, a senior administration official said, but America and China as well.

“It’s part of a strategy in which China risks seeing the United States forming alliances in its neighborhood, which may not be to Beijing’s liking,” said the official, who spoke on condition of anonymity. Likewise, Mr. Obama’s decision to accelerate the recent deployment of an American aircraft carrier group to the Yellow Sea for joint exercises with South Korea was meant to send a message to Beijing. Aware that China doesn’t like any kind of display of American military might in its backyard, Obama administration officials are hoping to change Beijing’s cost-benefit analysis until it decides that restraining North Korea is a lesser evil than seeing more American sailors playing war games outside its door.

But Mr. Rothkopf said that it will take more than pressure to get Beijing to yield. “We have moved from the cold war era of bipolar reality through the brief bubble of sole superpower unilateral fantasy into a world of a new multipowered system which requires old-fashioned balanceof- power diplomacy,” he said.