The U.S.-Chinese relationship, already being tested by rising trade tension during President Obama's first year, has been rocked by new turbulence as the administration has sought to prove its commitment to human rights around the world.
The two governments are at odds over planned U.S. arms sales to Taiwan, American overtures to Tibetan exiles and, now, the issue of Internet freedom that has been vividly raised by allegations against China from Google.
After Secretary of State Hillary Rodham Clinton complained Thursday in Cold War terms about China's Internet intrusions, Chinese officials shot back Friday that her remarks were "harmful to Sino-American relations" and demanded that U.S. officials "respect the truth."
The exchange set off a diplomatic shuffle. Top U.S. and Chinese officials have huddled in a series of hastily convened meetings in Washington since Clinton's speech to discuss the Google issue and "the broader aspects of our relationship," Philip J. Crowley, chief State Department spokesman, said Friday.
Some experts believe that Clinton may have been too provocative when, in Churchillian tones, she lamented that "a new information curtain is descending over much of the world." But her remarks, in a major prepared address, highlighted the Obama administration's hardening approach.
The U.S. tack comes as Beijing is being increasingly resistant to foreign pressure. In addition to its stern posture on Tibet and Taiwan, China has rebuffed calls to revalue its currency and support a global climate change treaty.
"We're in for tough sledding for the rest of the year," predicted David M. Lampton, director of China studies at Johns Hopkins University's School of Advanced International Studies.
Diplomats and analysts worry that the expanding array of disputes could damage chances of Chinese cooperation on key U.S. strategic issues, such as North Korea's nuclear program, sanctions against Iran and the international effort in Afghanistan.
Analysts said the new frictions could affect cooperation between the two nations' militaries, an initiative announced in November by President Obama during a visit to China. They also could prompt the Chinese to rethink plans to take part in high-level meetings, such as Obama's planned nuclear security conference this spring.
Last year, Obama administration officials, eager to begin their relationship with China on a positive note, focused on areas of mutual interest while putting off tougher issues. But the relationship took a turn for the worse, in the Chinese view, after the U.S. imposed duties on Chinese tires and steel pipes. Sensitive issues, such as the U.S. relationship with Taiwan and Tibet, continued to stack up.
Meanwhile, the administration has been criticized by human rights advocates for not pushing more forcefully in its dealings with China and other countries.
The criticism comes as Obama has faced other questions concerning international diplomacy, and it coincides with the approach of U.S. midterm elections. Meanwhile, the Chinese, too, have begun to think about a big political event: their 2012 party congress, when a new leader will be chosen.
"With an election period coming up, nobody wants to appear unduly solicitous or weak," Lampton said. The debate over Internet freedom captured world attention last week when Google complained of attacks on its network from China and said it might shut down its Chinese-language search engine if the government didn't stop requiring that it censor searches.
But Clinton's speech was the first in which the administration suggested that Internet freedom would be a key plank of its foreign policy.
Clinton specifically criticized the Chinese and others for Internet censorship. And she suggested that defense against cyber attacks was a core issue of mutual defense for the United States and its allies.
"This was definitely a shot across the bow," said Charles A. Kupchan, a National Security Council aide in the Clinton administration. "This is a level of rhetoric vis-a-vis China that is new."
The initial Chinese reaction was to try to play down the speech, portraying the issue as a narrow commercial dispute.
But the Foreign Ministry made an about-face Friday, saying in a statement that the U.S. needed to "respect the truth and to stop using the so-called Internet freedom question to level baseless accusations."
Meanwhile, U.S. officials are expected to soon approve the sale of billions of dollars worth of missile defense batteries and helicopters to Taiwan.
Obama is also expected to meet this year with the Dalai Lama, the exiled spiritual leader of Tibet, whom the Chinese consider a separatist. Last year, Obama declined to meet him, sparking condemnations from human rights advocates in the United States.
Kupchan, who is now with the Council on Foreign Relations, said that while he does not believe the two countries are headed for a major crisis, "there has been a certain amount of brinkmanship."
"We'll probably see in a week or two whether we're in for a tougher period, or whether they're uncomfortable with how the tensions have risen so quickly, and step back," he said.