WASHINGTON - One of the first  things I learned many years ago as a  foreign correspondent was that one can understand a country best by focusing on its peripheries not its center.

It is the geopolitical counterpart of understanding a man's real character most accurately by observing how he treats not his wife, but others.

So let us start with some apparently peripheral facts about China today. The legendary old Burmese city of Mandalay is now essentially a Chinese city.

Chinese is already one of the three major languages in the Russian Far East; and in the restive province of Sinkiang in Central Asia, Beijing has moved so many Han Chinese out there that the Chinese outnumber the native Turkic Uighurs.

We naturally chalk up this mass emigration from the center to security, oil and historical Chinese expansionism. In part, it is. But these symptoms of, change also have another crucial reason that is growing in urgency every day. China is running out of water.

A few of the facts: Of population packed China's 617 cities, 300 are facing serious water shortages, most of whose shortfalls can be filled, if at all, only by diverting water from agriculture. The Yellow River, which could be said to be China's Mississippi, went dry and failed to reach the sea for 226 days out of 365 in 1997 (the first time in history that it went dry was in 1972, and the number of dry days has been increasing ever since).

So many of the irrigation wells in Shandong province in the north were not pumping last year that Chinese water analysts reported frenzied well-drilling by desperate farmers. Shanxi province was always known for its Fen River.

That river no longer exists, and the authorities there have gone from pumping water at 300 feet down to 2,500 feet. Finally, American intelligence satellite photos have shown that the entire north of China is literally drying out. '

It would be interesting enough if those alarming facts came only from environmentalists,but there is another concomitant developments. China s already looming water shortage, as well as other environmental disasters-in-the-making, is suddenly the business of U.S. intelligence agencies. This is happening to such an extent that we might soon talk about "environmental security."

To cite one example, in recent months the National Intelligence Counci1, an   umbrella group of U.S. intelligence agencies, commissioned a group of 65    distinguished American scientists, in what is called the MEDEA project, to look into the groundbreaking work in these areas done by Washington s Worldwatch Institute. The scientists effectively confirmed Worldwatch's findings that water scarcity is becoming extremely critical in China and must be dealt with soon.

"Factors such as erosion, salinization effects of air pollution; fluctuations in      weather patterns and especially availability of fresh water will limit the productivity of China s arable land," the MEDEA study concluded. "Appropriate      policies, including greater reliance on world grain markets, will be critical China's agricultural prosperity."

Worldwatch President Lester Brown, whose work on "Who Will Feed China?" in 1995 kicked off all of this speculation and confirmation on how China was becoming ecologically unsustainable, and thus potentially politically unstable, carries the discussion further in his recent publication "Vital Signs."

"China is telescoping history so that we can see the effects of development," he says. "We’ve never seen anything like it in the history of the world, and water is the real sleeper. China is the first region of the world in which water has emerged as a major problem, and as countries push up against the limits of their water systems, anything is possible.

"Any major threat to China’s food self-sufficiency, if not addressed by strong new measures, would likely push up world grain prices, creating social and political instabilities in Third-World cities. These problems are now clearly linked to global security. Indeed, we’re beginning to recognize the need to redefine security."

It is still too early to see exactly what This new knowledge will mean to the actual practices of American intelligence, Security and diplomacy.

But we do know that there are many Sleepless nights among authorities in Beijing, who are fully aware of all of This, even while their population is rising From its present 1.2 billion to an estimated 1.5 billion by 2025. We do know that Historical developments such as water scarcity or food imbalances inevitably Lead to civil unrest, wars and even to the Downfall of empires such as the Maya and many of those in ancient Mesopotamia.

For China’s part, one can predict that If the country does not swiftly come up With a comprehensive program of conservation, greater population control and Better planning, Chinese immigra- tion to the Mandalays, the Siberias and the Sinkiangs will become even more massive than it is today. That is a fact that should keep people awake nights, and not only in Beijing.

Meanwhile, the good news is that American officials are beginning to take the environment seriously as a causal effect in human behavior, and one that we can even with substantial accuracy predict. Let’s hope they continue the good work.