Of the many competing forecasts of the century now unfolding, all agree that the rise of China will be a central determinant of its course. So great is China's potential that some have prematurely termed this the "Chinese century." Once hazily distant, that imagined prospect is rapidly becoming a tangible reality right before our eyes.

In its scale and speed, in the ambitions of its leaders and hopes of its people, this development is unprecedented. Far from maturing into a more settled pace of change, the rate appears to be accelerating and broadening as more and more of the country is drawn into the modern world.

Were China a country of modest size, this process would be an interesting, even fascinating, one, with soft ripples of influence confined within nearby horizons. But China is one fifth of humanity. Its enormity ensures that there can be no insulating boundary between its internal transformation and the world outside. Our attention is focused on the dramatic developments within that country, but we are simultaneously witnessing the emergence of a new and powerful actor on the global stage, one whose actions and decisions will reach deeply into every country on the planet.

Into the World

China's rapidly rising power is already extending its influence around the world long before it or the world is ready. This is most evident in international commerce, where the country's seemingly inexhaustible capacity for economic growth is producing unsettling effects in countries all around the globe. And it is doing so with little deliberate intent by the government.

This phenomenon will only increase as China's economic ascent inevitably endows decisions made by its leadership regarding purely domestic matters with increasingly far-reaching effects on the world outside. Ignorance of, or indifference to, this interconnection by the Chinese leadership is certain to result in a negative impact on the fortunes of the globe, and eventually on their own as well, as the rising debate over the exchange rate attests.

Permeable borders and integration into the world and its economy will rudely awaken those in the leadership who dream of combining a lordly autonomy with increasing prosperity. Many hard lessons await those who fail to comprehend that the advancement of their own interests requires an understanding of the interrelationship between their actions and the well-being and forbearance of the rest of the world.

Nevertheless, in every country, the fool's gold of pure selfishness seduces many with its promise of unshared riches, and we cannot be confident that the leadership in Beijing will soon accept that their country's interests cannot be secured if paired with an indifference to the fortunes of others.

Transforming the World

Because of its enormous size, China cannot fully enter the world without transforming it, even as an entirely passive actor. But passivity is unlikely to become a defining characteristic of its foreign policy. China's economic prowess is making possible rapidly expanding military capabilities and political influence. These must inevitably bring with them the temptations of an increasingly ambitious agenda. The salient question is how China will choose to employ its new and unfamiliar power.

China's expanding reach will ensure that its relationship with the U.S. steadily grows in terms of issues, opportunities, and dangers. This is already evident in East Asia, where China's advent has initiated a sober recalculation of interests by the countries in the region and where the U.S. continues to assume a prominent role ensuring the region's security. A collision is far from inevitable, but only if both countries actively seek to avoid it.

But the deepening changes in East Asia only hint at what is to come. China's impact will be a global one and is certain to refashion many of the patterns and relationships of the post-World War II international system. Even if China treads lightly, this familiar post-war order will be significantly altered, perhaps even displaced by something much different, and with unpredictable results.

For over half a century, the U.S. has been the most important actor in the global system of states. America's immense resources and its towering position made possible by widespread devastation elsewhere allowed it to extensively refashion the post-World War II international system.

But the most important feature of the post-war international order has been the willing acceptance by the United States of the principal responsibility for ensuring the stability and security of the international system as a whole, to be accomplished multilaterally if possible, but unilaterally if necessary. Some may regard this self-created role as arrogant paternalism or even imperialism, but none can deny that it has been intrinsic to the establishment and maintenance of the existing international order.

For all of its undoubted benefits, in many ways that global reach has been too sweeping and too successful. After six decades, most countries, including close allies, have become accustomed to the U.S. tackling the world's security problems while they devote their attention to promoting their own, more narrowly conceived, interests. Whether it be North Korea, Colombia, the Arab-Israeli conflict, the Balkans, Libya, the confrontation between India and Pakistan, the Caucasus, or anywhere else, most of the world reflexively assumes that the U.S. will take the lead in addressing whatever problems arise.

That is the world in which China's emergence is taking place and which it may soon be instrumental in transforming.

Those who decry the unilateral efforts of the United States as arrogant and pernicious often express their preference for the benefits of a multipolar world in which the rise of China and other aspirants will offset the hitherto unrivaled power of the United States. They may soon get their wish. With the emergence of each new major actor, the ability of the United States to act unilaterally will be further constrained.

In this new world, if stability and security are to be secured to any useful degree, a truly collective and cooperative sharing of general responsibility will be required, with China taking a prominent role regarding leadership and commitment of resources.

Fearful Signs

I regret to say that many of China's current policies provide little encouragement. In truth, many are quite disturbing. This is dramatically evident regarding the proliferation of nuclear weapons, technology, and expertise, which poses an unparalleled threat to the world and which every responsible state has a stake in halting.

Currently, both North Korea and Iran are attempting to arm themselves with nuclear weapons. The United States has taken the lead in trying to prevent this frightening prospect from becoming a reality, but it has thus far received only modest assistance from others.

China's role has fallen between offering begrudging help and doing outright harm. In North Korea, China possesses vastly greater influence there than it modestly claims and could, if it wished, bring far greater pressure on a regime which would in all likelihood be unable to survive without China's support and the unobstructed transit of food and fuel across its borders. And yet despite repeated requests, China has brought only the mildest pressure to bear on Pyongyang, and with very limited results. Frustrating the United States in its efforts and entangling it indefinitely may have its attractions to Beijing, but the result has been to allow and even encourage a dangerous and unpredictable regime to progress in its deadly efforts. Does the Chinese leadership genuinely believe that a nuclear-armed North Korea will never pose a threat to it?

In Iran, the militant theocracy has expended great effort and resources on secret programs over the past two decades in its determination to acquire nuclear weapons. The consequences of success would be alarming, with transfers to terrorists and others suddenly made possible. A loss of control due to domestic disturbances or the actions of autonomous actors as occurred in Pakistan will remain permanent threats. But even as the United States attempts to persuade the international community to take action to prevent this extraordinary threat to the world from becoming a reality, Beijing has made clear its determination to veto any effort by the United Nations to do so. This stunningly short-sighted and irresponsible position may result from the short-term attractions of currying favor with a potential ally, one increasingly important in terms of China's growing need for oil. But the cost will be the emergence of a permanent threat. Nuclear weapons in the hands of terrorists are as easily employed against Beijing and Shanghai as they are against Washington or Tel Aviv. Once Iran has possession of them, the threat will never go away.

I will refrain from addressing the frightening impact that China's aid to Pakistan's acquisition of nuclear weapons has had on the world except to say that the technology and expertise has now been disseminated around the world. Is it at all possible that the leadership in Beijing believes that they and their country are permanently immune from the effects of this profound degradation of the world's security that they have been instrumental in bringing about? I am truly at a loss to explain it.

Such behavior illustrates the dangers of ignoring the relationship between one's own interests and those of the wider world. Beijing may in fact have acted with complete unconcern for the consequences on others of its pursuit of these selfish objectives, but it has thereby dramatically degraded its own security and probably done so indefinitely.

Mr. Hyde is a Republican congressman from Illinois and chairman of the U.S. House of Representatives International Relations Committee. This is an edited extract from his speech, "Hong Kong, China, and the World," to yesterday's Heritage Foundation luncheon in Hong Kong.