'SAME bed, different dreams" is one way to describe U.S.-China relations: Though the two powers share the blue waters of the Pacific, they are in many ways oceans apart.

Yes, Secretary of State Colin Powell sees it in a much more positive light: "U.S. relations with China are the best that they have been since President Nixon's first visit [in 1972]." Certainly, relations are more stable now than in the Clinton years, when U.S. policy on China looked a lot like a rollercoaster ride.

But the relative calm is no reason for giddiness.

In fact, the relationship is far from trouble-free. And if it were not for the mutual interests found in the War on Terror and in eliminating North Korea's nuclear-weapons program, the relationship might be considerably more contentious than it is today. (Remember April 2001, when an aggressive Chinese fighter collided with a Navy EP-3 reconnaissance plane, and Beijing held its crew against U.S. wishes for 11 days?)

Though China has helped get North Korea to the bargaining table and played an even more limited (Sino-centric) role in the War on Terror, serious concerns remain: human rights, weapons proliferation, trade and Beijing's prodigious military buildup.

Some may argue that the Chinese people are freer today ever before. But by 21st century human-rights standards, the People's Republic of China (PRC) falls far short of internationally accepted norms.

In its 2002 Human Rights Practices report, the State Department called China "an authoritarian state in which the Chinese Communist Party is the paramount source of power." It had been hoped that vibrant economic growth would loosen the party's Mao-jacket collar a notch or two, but the PRC recently began quashing a lively national debate (mostly on the Internet) among China's 1.3 billion people on political reform, constitutional amendments and coming to grips with the 1989 Tiananmen Square crackdown.

China's record on the proliferation of weapons of mass destruction (WMD) is also troubling. The CIA has branded China a key supplier "of WMD and missile-related technology to countries of concern." Last week, for the second time this year, Washington sanctioned Beijing because a state-owned firm, NORINCO, sold advanced missile technology to Iran. Beijing is also deemed the midwife of Pakistan's nuke, which enabled Islamabad to provide nuclear-development help to both Iran and North Korea.

China's economy is one of the world's largest and most dynamic, with reported annual growth of 5 percent to 10 percent in recent years. But the U.S. trade deficit with China, just $12 billion in 1992 but $103 billion last year, could reach a record $130 billion this year. Congress grows ever more frustrated that China's unfair trade practices, fixed exchange rate and unwillingness to open its economy (as required by its entry into the World Trade Organization) are costing America jobs.

Finally, China's runaway military modernization program seriously concerns U.S. military planners. Beijing continues to lap up the best Russian-made fighters, submarines, and destroyers money can buy, creating world-class pockets of excellence in China's military. Its large indigenous ballistic missile arsenal, including 450 missiles aimed at the island of Taiwan, is no comfort either.

The Pentagon worries that China will try to determine democratic Taiwan's future militarily. (Beijing claims that Taiwan is but a renegade province.) Any forcible attempt by China to reunify with Taiwan would contravene American promises (and laws) to assist in Taiwan's defense - and likely involve U.S. forces.

China's mystique and its seemingly boundless market has mesmerized America ever since 1784, when the trading ship Empress of China sortied from New York harbor bound for Canton. To this day, people gazing upon China see what they want to see.

It's important that we see the PRC for what it really is - warts and all. And understand that despite a quiescent period, our national interests and aspirations, and China's, have not been, and in the future will not likely be, the same

We must be prepared for turbulent times as well.

Peter Brookes, a senior fellow for National Security Affairs at the Heritage Foundation.