The humanitarian catastrophe in East Timor, coming so soon after the war over Kosovo, provides a vivid reminder of how political turbulence within states is upsetting world order. Such turbulence presents challenges for the United Nations--the embodiment of organized international society--and for the United States, the sole government with both the logistical capabilities and leadership to mount interventions in any part of the world.

Where does this pattern of recurrent ethnic conflict and humanitarian catastrophe lead? It is impossible to know whether the decades ahead will see a continual increase in the number of sovereign states--193 today--or will bear witness to powerful movements of regional consolidation under the aegis of a few dominant giants. Equally uncertain is whether the world community will accept a growing responsibility to protect people against internal ravages or, alternatively, will become disenchanted with such rescue missions because they so often backfire or because the costs of success seem too high.

What helps make these challenges especially bewildering is that they emerge at the intersection of two sometimes-conflicting principles: respect for territorial sovereignty of the state and the right of self-determination enjoyed by the peoples of the world.

In many ways, this is a new problem. Throughout the several decades of the Cold War, these two principles coexisted fairly well. Claims for political independence were limited to situations that did not involve dismembering any existing state. The main context of self-determination involved the dynamics of decolonization--and countries in both the East and West, along with the leadership of the Third World, accepted the idea that colonial borders would be respected during transitions to independence. There were challenges along the way, of course, involving Tibet in relation to China, the Ibos in relation to Nigeria, and Kashmir in relation to India, but in these instances the territorial sovereign has successfully resisted secessionist moves. Only Bangladesh, with India's help, was able to shatter the unity of Pakistan after a bloody, genocidal ordeal in 1971 that sent as many as 10 million refugees into India.

This pattern of limiting self-determination was endorsed unanimously by the U.N. General Assembly's important 1970 Declaration of Principles of International Law Concerning Friendly Relations Among States. It was a kind of Faustian bargain that meant consigning restive minorities to oppressive regimes in exchange for an agreed principle of order that recognized the primacy of the sovereign state within its own territory. Such a bargain has always seemed like a kind of moral backsliding: Hadn't the international community recognized after 1945 that it had tragically neglected the plight of Jews in Germany during the Nazi period, and that it must never again turn away from such persecution on the grounds that it is occurring within sovereign territory?

There is troublesome irony here. Without the threat of World War III, the bargain seems less necessary, and hence cynical, yet its erosion has precipitated a series of outbreaks of ethnic conflict accompanied by a surge of nationalist sentiments among smaller and smaller ethnic groups. Several developments--set off by the ending of the Cold War--unraveled the bargain. The quick recognition of the recovery of statehood by the Baltic countries and then the other republics that had composed the Soviet Union set a major precedent: Self-determination could now be realized under certain conditions even when it disrupted the unity of a state. In this instance, the process seemed spontaneous, a largely voluntary adjustment to the collapse of the Soviet Union and its internal empire.

But subsequent developments in the former Yugoslavia were less reconcilable with the older bias against involuntary claims of secession. European diplomacy, led by Germany, quickly moved to recognize Slovenia and Croatia as states in 1991, denying Belgrade the right to maintain Yugoslavia's unity.

As has been understood from the moment the idea gained currency in the days after World War I, self-determination is a highly combustible concept that can be used in many contradictory ways. Because international law vests this right in "peoples" rather than in either "nations" or "states," there is plenty of room for interpretation. Recently, self-determination has been used to assert claims of indigenous peoples to safeguard the autonomy of their traditional homelands and ways of life, and by minorities who are targets of ethnic hatred.

But it is not enough to try to explain the turbulence today merely by reference to the ambiguities of practice and concept. Another powerful effect of the ending of the Cold War has been a weakening of geopolitical discipline. The Soviet state successfully suppressed ethnic nationalisms within its sphere of influence. But a wide array of Euro-Asian nationalisms that simmered under Soviet rule were never fully extinguished. After the Soviet collapse, these ethnic nationalisms resurfaced as movements seeking independent statehood.

The West, too, relaxed its geopolitical grip. It was no longer as fearful of realignment emerging from internal political turbulence, or of risks of competitive interventions as had occurred in Vietnam and Afghanistan. It halted its subsidy of artificial or weak states that were friendly, thereby allowing the strains within civil society to exert themselves more potently. For instance, the West had invested heavily in the stability of Yugoslavia during the Cold War, when the Yugoslav army was seen as important to the defense of Europe. After 1989, such considerations no longer applied, and a sharp reduction in external financial support contributed to a rise in anti-Serb nationalism.

This loss of strategic value also affected the stability of sub-Saharan Africa. Whereas both Moscow and Washington had once invested heavily in keeping particular governments in firm control, the incentives to do so in the post-Cold War years disappeared. Countries such as Zaire (now Congo) were no longer strategic battlegrounds. Additionally, human rights considerations often reinforced the idea that these countries were no longer strategically important, especially in instances where authoritarian and corrupt regimes had long been kept in power because they were geopolitically reliable.

In addition, the worldwide spread of consumerism has threatened traditional identities in many societies, producing a chauvinistic backlash against alleged threats of Westernization, or even "McDonaldization." The state is seen as weak and ineffectual, and extremist movements take shape based on particular ethnic or religious identities. The rise of market forces, including the pressures exerted on states by the International Monetary Fund and the World Bank, have seemed to erode further the capacity of the state, shifting loyalty to ethnic and cultural identities, and often provoking severe conflict.

It is against this background that the most recent challenge in Indonesia can best be judged. East Timor can be viewed as unfinished business from the colonial era. Almost as soon as Portugal had granted independence to East Timor, Indonesia moved in 1975 to annex the new state by brute force--resembling in many ways what Iraq attempted to do with Kuwait in 1990. The revealing difference involves the geopolitical climate, which clouded over Indonesia's aggression, while a full-scale counterattack was mounted 16 years later in support of Kuwait. Now with moves toward independence for East Timor provoking a horrifyingly bloody repression, the climate is again different. Indonesia is no longer the vital Cold War ally it was in the mid-'70s. Human rights and self-determination have grown far more important in recent years. The East Timorese have made their case effectively in the court of public opinion, making it difficult to turn away from their torment, especially since its ugliest expression was provoked at the end of last month by their turn to democratic means in the form of a U.N.-monitored referendum on the future of the territory.

But it is impossible to draw generalizations from the specifics of East Timor. Each situation presents a unique set of relevant factors. The legal framework involving the right of self-determination and respect for territorial sovereignty is in disarray. Deference to the state has certainly weakened in recent years, but the United Nations is either unable to produce a consensus among its members or is expected to act on the basis of some vague mandate without having access to sufficient financial and military capabilities. (Both Kosovo and East Timor illustrate experiments in forging cooperation between regional players and the U.N., with a strong orchestrating role being played by the United States.) And always, there is need to take account of the strategic calculus and the relation of a given country to the world economy. Thus, it is impossible to do much about Tibet or Chechnya because the costs of intervention seem far too high, or to address the ethnic strife and genocidal politics in sub-Saharan Africa because the public concern and strategic gains seem too small.

It is clear that the international debate on the themes of humanitarian intervention and self-determination will remain salient throughout the next decade. Unfortunately, there will probably be a series of humanitarian catastrophes during that time that invite response, with neither the United States nor the U.N. able to produce convincing success. On the level of international law, it is too late to get the genie of self-determination back into the bottle of state sovereignty. The best we can hope for is some sort of compromise. Both Kosovo and East Timor suggest the form it might take: no support for claims of self-determination that would shatter an existing state unless a people is being victimized by genocidal behavior, by repeated crimes against humanity, and--in exceptional cases--by severe abuses of basic human rights that are targeted at a given ethnic community and sustained over a period of years.

What else can be done to address the needs of minorities without disrupting legitimate sovereign rights? Perhaps, as seems the case in Western Europe, the formation of strong regional communities will lessen the insistence on separate statehood. Another promising line of response is to maintain the unity of the state but grant substantial rights of autonomy and self-administration--an arrangement that could address the Kurdish challenge afflicting several Middle East countries. Far more reliance on preventive diplomacy would also help, heeding the sorts of early warning signals that were abundantly present in both Kosovo and East Timor; the successful deployment of a small deterrent peace force for several years apparently helped to prevent the spread of ethnic violence to Macedonia.

No challenge is more likely to test the maturity and morality of American global leadership in the years ahead than its ability to address these various instances of humanitarian catastrophe that threaten the unity of sovereign states.

Richard Falk is the Albert G. Milbank Professor of International Law and Practice at Princeton University and the author of "Predatory Globalization" (Blackwells).