The United States and China marked the 25th anniversary of the establishment of formal diplomatic relations this week.
The anniversary comes as both U.S. and Chinese officials say relations between the two countries are at their best since ties were established a quarter-century ago.
Normalization of relations on January 1, 1979, happened almost seven years after President Richard Nixon became the first U.S. leader to visit Beijing since China's 1949 communist revolution.
President Nixon made the visit in 1972 during the height of the Cold War between the United States and the Soviet Union. China had by then split with its Soviet allies, and Washington saw an opportunity to counterbalance Moscow's power by creating an alliance with Beijing. On the eve of the historic trip, President Nixon explained his vision.
What we must do is find a way so that we can have differences without being enemies in a war," Mr. Nixon said. "If we can make progress toward that goal on this trip, the world will be a much safer world."
Gradually, China adapted its economic policies and adopted free market reforms. Its economy is now the fastest growing in the world and it is the United States' second largest trading partner and its number one partner in foreign direct investment, not counting Hong Kong and Taiwan.
Politically, the two nations remain apart. Despite economic reforms, China is still a communist nation, and is showing no signs of adopting a U.S. style democratic system. Prime Minister Wen Jiabao recently told the Washington Post newspaper that China is not ready to reform its one-party system, saying illiteracy is one reason why the government believes conditions are not ripe for direct elections.
The United States has also been critical of China's human rights record.
Analysts describe the Sino-U.S. relationship as one of ups and downs over the past 25 years.
Relations suffered after Beijing's violent 1989 crackdown on pro-democracy demonstrators at Tiananmen Square. Tensions also rose in 2001, when a U.S. surveillance airplane collided with a Chinese fighter jet over China's southern Hainan Island, an incident that raised tensions on both sides of the Pacific.
China also continues to protest U.S. military support for Taiwan, which Beijing considers part its territory.
Very recently, relations between the former rivals have soared as China assumed an important role in brokering negotiations to end the North Korean nuclear crisis. As North Korea's closest ally, Beijing's role has been central to keeping the lines of communication open as the United States and other nations work to convince Pyongyang to dismantle its nuclear weapons program.
U.S. Secretary of State Colin Powell recently said the United States welcomes a global role for China, and praised its cooperation on the North Korea issue.
On the Chinese side, officials say they appreciated President Bush's moves to clarify U.S. policy toward Taiwan. The U.S. leader recently said the United States opposes any unilateral decision by China or Taiwan to change the island's current status. China had earlier been critical of what it had labeled as Washington's ambiguous policy on Taiwan. For years after the communist revolution in 1949, the United States recognized only the nationalist-ruled Taiwan. That shifted to the Communists after the United States recognized China in 1979.
Despite the current good state of relations, Chinese officials say they are weary of the view of some U.S. politicians who see China as a strategic rival.
Pan Shaozhang is a retired professor at Beijing's Foreign Affairs College, an institution affiliated with the Chinese Ministry of Foreign Affairs.
"China is rising and is becoming stronger and stronger as a whole," he said. "But a lot of people who treat China as a potential rival forget that China is a terribly poor country."
With per capita income in China at about $1,000 a year, Mr. Pan says he does not see his nation rising to superpower status anytime soon.
"China in the foreseeable future will not be able to, or wanting to, dominate the world," said Pan Shaozhang.
For now, he says China realizes that it is strategically and technologically dependent on the United States as Beijing tries to modernize. China also benefits from jobs generated by export firms, any of which are U.S. joint ventures.
Analysts say American companies are benefiting from China's relatively cheap labor and its huge market for U.S. products. Others say the economic partnership with China is costing American jobs. A ballooning $30 billion trade deficit is fueling anger among U.S. labor groups and others who say an influx of cheap Chinese imports is leaving millions of Americans without jobs.
Charles Martin, the president of the American Chamber of Commerce in China, says that despite the ongoing trade tensions, he is optimistic that ties will continue to deepen, and that both sides will profit.
"The U.S. and China are the two most dynamic economies in the world," he said. "They are complementary, largely, rather than competitive. "
Mr. Martin says that if China and the United States can manage their political differences and help each other resolve political problems, it is going to be a relationship that can only grow stronger.