WASHINGTON — Secretary of State Hillary Rodham Clinton has moved aggressively and quickly to secure a stronger role in what she has called the world's most important relationship: U.S. dealings with China. But military and economic tensions between the two powers keep getting in her way.

As the international financial crisis worsens, the two colossal economies have bickered over their intertwined interests. China is nervous about its position as Washington's biggest foreign creditor, holding an estimated $1 trillion in U.S. government debt.

Beijing and Washington also have sparred over military matters, including a confrontation between American and Chinese vessels in the South China Sea and harsh words over Pentagon claims that China's rapidly growing military strength could allow it to win short, intense conflicts against high-tech adversaries.

These issues will demand high-level attention from the Treasury and Defense departments. Clinton is pushing, however, to ensure that her diplomatic corps is not marginalized as the United States engages a country the Obama administration needs as a partner in efforts to solve the world's major problems.

Clinton began staking out her claim on China early. A week after President Barack Obama's Jan. 20 inauguration she signaled her determination not to stand on the sidelines in her first comments to reporters at the State Department.

"The strategic dialogue that was begun in the Bush administration turned into an economic dialogue," Clinton said. "That's a very important aspect of our relationship with China, but it's not the only aspect of our relationship."

In Beijing last month, on her first foreign trip as secretary, Clinton said she and new Treasury Secretary Timothy Geithner "will both be fully engaged" in discussions with China. Clinton then pleasantly surprised China by saying the Obama administration would not let its human rights concerns interfere with cooperation with Beijing.

Clinton's efforts mark a change from the Bush administration. George W. Bush's treasury secretary, Henry Paulson, led the main discussions with China; former Secretary of State Condoleezza Rice relied on her deputy to handle another set of talks.

Inevitably, with the world economy in danger, treasury will continue to play a top role in dealings with China.

Elizabeth Economy, Asian studies director at the Council on Foreign Relations, said Clinton moved quickly in "capturing the China portfolio, but given the nature of the relationship between China and the United States, there's no doubt that trade, currency and investment issues are going to be front and center."

Geithner is consumed with efforts to lift the U.S. economy, and this might allow Clinton to take an early leading role. But, Economy said, the State Department lacks "the depth and the breadth to manage the full range of economic issues with China."

The global financial crisis has dominated recent discussions between the countries, and it will top talks between Obama and Chinese President Hu Jintao at the London meeting of leading economies next week.

In addition to numerous smaller forums, the Bush administration set up two major dialogues with Beijing: the Strategic Economic Dialogue, which were high-level, twice-a-year discussions, led by Paulson; and the Senior Dialogue, led by the deputy secretary of state, the No. 2 department official.

Despite all the talking, Bonnie Glaser, a China specialist at the Center for Strategic and International Studies think tank, said there remains a "profound level of distrust between the sides."

The Obama administration has not yet outlined specifics for official dealings with China, although it seems likely that Clinton will take over the Senior Dialogue.

Still, it is unclear how much time Clinton, who must address tensions in the Middle East, South Asia, North Korea and Latin America, will be able to devote to the China relationship.

And then there is the matter of what China wants.

Economy said China would be happiest with a long-running dialogue that does not require major policy changes.

"The United States usually comes to China with a pretty long list of what we want China to do, and, for the most part, what China wants is to be left alone," Economy said.



EDITOR'S NOTE: Foster Klug covers U.S.-Asian affairs for The Associated Press.