Until recently, the exhortation has been faithfully followed by his successors, Jiang Zemin in the 90s and Hu Jintao in the new millennium. Under Jiang, Deng's reform and opening up policies took root and the once moribund economy sprang back to life. Hu stepped into Jiang's shoes in 2002 and presided over China's “peaceful rise” to a big-power status.

The rise was so rapid that it has stunned the world and made China dizzy with success. It seemed hard for China's leaders to stick to Deng's teachings. And they have plenty of reasons to show assertiveness, confidence, and even hubris.

First, it was beyond the wildest dreams of Deng, the “chief architect” of China's reforms and opening, to expect that China could have ever become the world's second largest economy in 2010 in a short span of three decades. When Deng set the “hunker-down” foreign policy in the late 1970s, much of the country lived below poverty line. This year, according to IMF, China's GDP would amount to US$5.3 trillion, surpassing Japan's US$5.2 trillion. China's per capita GDP would exceed US$4,000, compared with US$1,000 in 2003. A quadruple jump in seven years! It would make anybody dizzy.

Second, an economic backwater 30 years ago is now the biggest creditor country of the United States-the world's wealthiest superpower. What does that mean? Lawrence Summers, chief economic adviser to U.S. President Barak Obama, once asked pointedly, “how long could the world's biggest borrower remain the world's biggest power?” The unasked question is, “how long could the world's biggest creditor country remain the world's non-power?”

Well, a lot of people don't believe in statistics, especially those released by China, which are often inaccurate or even cooked. For skeptics, Novel prize economist Paul Krugman has an advice: seeing is believing. “China's economic success should be obvious even without statistics. For those who have visited Shanghai, did it look poor or backward?”

Third, China seemed the only country in the world which has weathered the global financial crisis relatively unscathed. It's gross domestic product grow by 8.7 per cent in 2009, above the benchmark 8 percent set by government. Does that show the “superiority” of their system? Chinese leaders certainly think so.

All these, plus a plethora of others, have fed a sense of national pride that is hard to conceal and much harder for the country to hunker down. It now seemed that Deng's exhortation has to be pigeonholed. China must have its day in the sun. So, in Copenhagen and at Davos, China's voices are heard and reverberated around the world.

Now, Beijing speaks with increasing assertiveness, and acts with growing confidence. It didn't hesitate to lecture the U.S and blame it for causing the global economic recession. It rejected U.S. demand for the revaluation of Renminbi, the Chinese currency which Washington says has been kept below its true value to make Chinese goods competitive in export. It brushed off criticism on human rights abuses. It sentenced dissident Liu --iaobo to 11 years in jail despite Obama's pleading. It executed a Briton for drug trafficking despite Prime Minister Gordon Brown's request for clemency. The list goes on and on.

Recently, there have been ominous signs that Beijing's diplomatic assertiveness is increasingly viewed by the rest of the world as unsettling and hubristic. As a result, the United States appears ready to hit back. A rough patch in Sino-U.S. relations is looming large. Last week, Beijing warned the United States in harsh language against President Obama's announcement of selling US$6.4 billion arms to Taiwan, demanding that Obama rescind the “mistaken decision” in order to avoid damaging broader U.S.-China relations. China is also adamantly opposed to Obama's planned meeting with the Dalai Lama, the spiritual leader of Tibet whom Beijing labeled a “splittist,” in the White House, saying the rendezvous harms China's core interest.

It should be noted that the U.S is not doing anything different from what it has been doing all along. But Beijing's reaction is different-unusually strong and vehement, and menacing. It bodes ill for relations between the world sole superpower and a rising power.

However, Liu Chao-shiuan, senior adviser to President Ma Ying-jeou, said last week that the escalating row between the duo, who called themselves “strategic partners” in happier times, may not spin out of control. But it poses threat to the national interests of both sides, because China and America are, in a sense, share a symbiotic relationship.

America, with a budgetary deficit exceeding 11 per cent of its GDP, the largest since World War II, needs China's lending. It also needs Beijing support to resolve many regional security issues, like stopping nuclear proliferation in Iran and North Korea. China needs America's market - the single largest source of its trade surplus and its overflowing foreign exchange reserves, which stood at a whopping US$2.4 trillion by the end of 2009.

That may be why Liu Chao-shiuan was still upbeat despite the gathering clouds over the horizon. Maybe Beijing should take another look at Deng --iaoping's exhortation, which included a slang warning his comrades against “swaggering” when China becomes prosperous one day.