MANY GOVERNMENTS around the world identify stopping and stemming "ethnic and religious hatreds" as a major foreign-policy priority. Quite simply, in the words of the 2006 U.S. National Security Strategy, such "conflicts do not stay isolated for long and often spread or devolve into humanitarian tragedy or anarchy." Yet, ethnic conflicts do not simply appear out of thin air. They can be traced primarily to the decisions of political leaders. The spread of ethnic conflict is not automatic either. For existing ethnic conflicts to move beyond their original borders, the relevant actors-ethnic communities, states and other private-interest groups-need to make a choice. If they choose to expand the conflict, they need three things: the motive, the means and the opportunity.

Ethnic conflict spreads in two principal patterns: diffusion and escalation. Diffusion means that the existence of one ethnic conflict leads to the occurrence of others, either elsewhere in the same state or in other, often neighboring, states. Escalation, on the other hand, describes a situation in which more actors become involved in the same conflict as belligerent parties.

The traditional patterns of the spread of ethnic conflict exhibit close links between escalation and diffusion and typically occur when ethnic groups mobilized on the basis of some combination of greed, grievance or security concerns confront each other, the states in which they live or both. Ethnic groups, states or a combination of both can drive these conflicts. They are predominantly played out on a regional level (e.g., in the western Balkans, in the Greater Middle East) and involve not only the immediate neighbors of an ongoing conflict, but they also draw in regional and great powers.

The literature on ethnic conflict is full of different theories about its ultimate causes. There are three common explanations. One focuses on cost-benefit calculations or "greed": conflicts happen when profit is to be made. A second sees social, political, economic and other grievances as powerful explanations as well. Here, the argument is that conflict happens when people are dissatisfied with their status compared to other groups in society or feel that their status is threatened. So conflict can become a strategy either to change or defend the status quo. Finally, the third considers the so-called security dilemma as central among the causes of ethnic conflict. When people perceive their survival as individuals and members of a group is at risk, they seek to avert this threat by using violence preemptively against those who they consider to be the main source of the threat.

In most ethnic conflicts, participants are motivated by a mix of profit, status and security considerations. This is important for the diffusion of ethnic conflict because one conflict can only spread within or beyond a given country if people elsewhere are receptive to it. They must be motivated to pursue their interests by means of conflict, and they need the means and opportunity to do so.

THE CONFLICT in Sudan is primarily driven by ethnic groups. In the Darfur crisis, the government, through the Arab janjaweed militias, is targeting local Darfurian communities. The government claims their attacks originally came in response to the western rebel groups-the Sudanese Liberation Army and the Justice and Equality Movement-challenging President Omar al-Bashir, but many label the conflict genocide.

When the thirty-year civil war between north and south was approaching a negotiated settlement in the first years of the twenty-first century, the rebel groups elsewhere in the country wanted a greater share in the emerging new political and economic bargain as well. Their motive was improved political and economic status. Neighboring Chad, in particular, was motivated to play a role in the conflict by its keen interest in weakening the regime in Khartoum; the Chadian government alleged that Sudan was the main sponsor of antigovernment rebels in Chad.

The Sudanese government had the means to carry out repression in Darfur in the form of the janjaweed militias. The western rebel groups, in the meantime, benefited from easy access to bases in Chad and received arms and equipment from there (as well as from Eritrea).

Opportunities presented by ongoing negotiations and international involvement in Sudan combined with motivation and means to make conflict possible. Having learned the "lesson" that violence pays by seeing it bring the government to the negotiating table, ready to make concessions, the movements in Darfur launched attacks against government forces. They even had a Plan B (for some of them it may even have been Plan A): if the government did not respond with concessions but with increased repression, then surely a humanitarian emergency would result. The international community would take sides with the local movements, shifting the balance of power away from the government.

As this case shows, the causes of the spread of ethnic conflict come not just from the local or state levels. This becomes more clear when one considers why neither Plan A nor Plan B of the Darfur movements worked. The Sudanese government was in a very favorable position that allowed it to pursue a policy of ruthless repression in Darfur. Equally as important as the existence of the means and motive was the international-opportunity structure. Initially, the African Union and UN mediators in the north-south conflict hesitated to become involved for fear of jeopardizing a settlement. This allowed Khartoum to negotiate a separate deal with the south and exclude Darfur from the so-called Comprehensive Peace Agreement of 2005. It was the close economic partnership between Sudan and China that protected the former from any hard-hitting action by the UN Security Council, despite the gravity of the human-rights violations in Darfur.

As the situation in Darfur worsened with mass killings and refugee flows, there was a second wave of diffusion, this time spreading directly into Chad and leading to an almost-successful coup against the government there. Military operations conducted by regular Chadian forces in Sudan in response in early 2008 also illustrate that escalation and diffusion are often closely linked.

Kosovo is another illustrative example of the complexity of the spread of ethnic conflict. At the extreme end, not just a case of diffusion or escalation, but simply the precedent set by Kosovo's independence is seen as a potential cause of conflict proliferation. Here, the initial conflict was also driven by ethnic antagonisms: Serbs and Albanians equally sought full control of Kosovo.

Control of means played an important part in halting the spread of the conflict. For ten years, successive preventive deployment missions-by the UN and later NATO and the EU-made sure that Macedonia was not dragged into the violence that engulfed the western Balkans throughout the 1990s. On the other hand, not having curbed the proliferation of small arms from Albania to Kosovo was one of the major facilitating factors that made the rise of the Albanian Kosovo Liberation Army (KLA) possible from the mid-1990s onward. The rise of the KLA-which called for the independence of Kosovo and was considered a terrorist group with links to organized crime, including by many in the West-was also aided significantly by a "tax" collected among diaspora Albanians in Western Europe and the United States.

The NATO-led intervention in 1999, motivated primarily by concerns over the grave violation of human rights in Kosovo, was an early example of escalation. At that time, Russia, too, resisted Western policy but eventually accepted Kosovo's UN-led administration under Security Council Resolution 1244. Almost ten years on, Russian resistance to Kosovo's unilateral declaration of independence and its recognition is far more uncompromising. While Russia has neither the means nor the opportunity to engage the West militarily, it may well contribute to the diffusion of the Kosovo conflict, albeit in a different way.

Kosovo is presented by Russia, and others, as an opportunity, a dangerous precedent for the creation of new states by unilateral acts of those seeking to realize their claims to self-determination through secession. That Kosovo has been able to pursue this path and find relatively widespread international recognition, it is argued, will inspire secessionist movements elsewhere to follow the Kosovo example. That it is unlikely this line of reasoning will have any practical merit-after all, even Russia has so far refused to recognize separatist regions across the former Soviet Union-is less important.

The very fact that self-determination movements elsewhere can now cite the case of Kosovo is likely to make the settlement of some of these conflicts more difficult because movements elsewhere will refer to Kosovo as a precedent based not only on the view of Russia, but also strengthened by similar pronouncements from China, Spain, Romania, Slovakia and Greece to name but a few. This has already affected, and will continue to affect, places as diverse as Sri Lanka, Indonesia, the Philippines, Thailand, India, China, Somaliland, South Sudan, Ethiopia and Tanzania.

Yet, diffusion is also likely much closer to Kosovo: Macedonia, with its roughly 25 percent ethnic Albanian population right across the border from Kosovo, and Bosnia and Herzegovina, with its highly discontent Serbian community, are perhaps the most likely early "victims" of diffusion. On the other hand, escalation in the sense of external belligerents entering the frame is unlikely. A strong NATO and EU military presence on the ground across the Balkan region will prevent or at least swiftly contain local violence. The still-feasible promise of closer relations with, and eventual membership in, the European Union is also likely to calm any desire for major trouble.

The "diffusion qua precedent" in the case of Kosovo when it comes to opportunities is instructive. Regardless of how one feels about the legitimacy and legality of Kosovo's unilateral declaration of independence, there is little if any need to turn it into an almighty precedent. Russia may be right in insisting that short of a new UN Security Council resolution, only a consensual separation of Kosovo from Serbia would have been legal under current international law. But waving the big stick of Kosovo as a precedent is counterproductive, not least in relation to any of the conflicts in Russia's own neighborhood. By the same token, the refusal, so far, to recognize Kosovo by several European governments such as Spain, Greece, Cyprus, Slovakia and Romania establishes a precedent where there is none-and a wrong one at that.

Kosovo is unique and requires a unique response-rejecting its independence with reference to other cases undermines this position and strengthens the very separatist forces that are meant to be deterred. By delaying or denying international recognition to Kosovo out of concern for the implications that such a move might have on suspected separatist movements in their own countries, these states are sending exactly the wrong message. For one, they equate their own problems with those of Kosovo. Yet, neither of these countries has Serbia's track record of past persistent and grave human-rights violations. Nor do people living in areas like Spain's Basque Country give the same strong support to independence as do some 90 percent of current inhabitants of Kosovo. Moreover, Northern Cyprus, another often-cited area that could "abuse" Kosovo as a precedent, in fact seeks reunification with the south. In 2004, they approved of a UN-sponsored plan to that effect, which was rejected by the south. So neither of these two cases, nor the situations in Slovakia and Romania involving ethnic Hungarians, are comparable to the situation in Kosovo.

WHEN THE spread of conflict is not driven by ethnic groups, it is driven by states. This is apparent in Iraq, an equally complex case of diffusion and escalation. Turkey's recent invasion of the Kurdistan region of northern Iraq was motivated by its own security concerns in relation to the terrorist Kurdistan Workers' Party (PKK), which has waged an insurgency against successive Turkish governments for over two decades. The threat from the PKK and Kurdish demands vis-à-vis Turkey in general, however, is perceived to have increased as a result of developments in Iraq. This also increases Turkey's motivation to be involved. The 2005 constitution formally established Kurdistan as a region in Iraq with far-reaching powers of self-government, including its own military forces. On the one hand, this allegedly gives Kurds in Turkey more incentives to ask for an equally advantageous status. More importantly, perhaps, it also means that Kurdish popular sentiment in Iraq might provide a power base and safe haven for the PKK, from which the terrorist organization may reinvigorate its campaign in Turkey.

Yet, the threat of diffusion and escalation does not end there. Other states could be equally motivated to play a part in the conflict. There are also sizable Kurdish communities in Iran and Syria. Further complicating matters, Iran and Saudi Arabia back different sides of another conflict driven by radicalized religious groups: the sectarian civil war between Sunni and Shia within Iraq. This could easily escalate further into a proxy war for regional hegemony. In addition, Iran, more than Saudi Arabia, also has an interest in making life as difficult as possible for the multinational coalition in Iraq, and has escalated the various interlinked conflicts in the Middle East, if only by using proxy forces like Hezbollah and Islamic Jihad.

Policy responses should take these actors' concerns into account and focus on eliminating potential spoilers of any settlement. So irredeemable PKK terrorists must be sidelined and deprived of their political and power bases. But this can only succeed if it happens in combination with acknowledging and addressing the legitimate grievances of Kurds by the Turkish government (a policy that has already begun), and a Kurdish acceptance, on both sides of the border, that violence is an unsuitable means to pursue otherwise legitimate ends. Above all, the current borders in the region must be recognized explicitly. This involves respect for the territorial integrity of both Iraq and Turkey, as well as for the right of Kurds in Iraq to their autonomous region.

The Turkish-Kurdish example indicates just how difficult it will be to remove motivations from the equation of diffusion and escalation of ethnic conflict. In many other cases, immediate success in this respect is likely to be equally difficult to achieve.

MORE RECENT, "nontraditional" patterns of diffusion and escalation reveal varied means and follow a different and more dangerous logic. Over the past several years, evidence has grown that there are increasing and solid links between ethnic conflicts on the one side and international terrorism and organized crime on the other. This has also created a new dynamic for the spread of ethnic conflict, and one that is much more difficult to tackle with the traditional set of responses aimed at containing and eventually settling such conflicts.

The links between conflict, crime and terrorism are, for example, particularly obvious in Southeast Asia, involving the Philippines, Indonesia, Malaysia and Thailand. At the center of a regional fundamentalist Islamic terror network is a group called Jemaah Islamiyah. It maintains links with similar groups, including the Abu Sayyaf group and the Moro Islamic Liberation Front in the southern Philippines, the Malaysian Kampulan Mujahidin, insurgent groups in southern Thailand, such as the Pattani United Liberation Organization, and the Free Aceh Movement in Indonesia. These links are primarily based on shared experiences of senior commanders in the anti-Soviet Afghan war in the 1980s and 1990s. They manifest themselves today in joint training, recruitment, financing and operational cooperation, and often involve direct and indirect links to terrorist groups in the Middle East, including al-Qaeda.

The various groups have exploited local grievances and grafted themselves onto preexisting ethnic conflicts, forming a dangerous, symbiotic partnership with local insurgents. They offer local fighters access to funds and know-how and receive in return a base from which they can wage their very own brand of jihad. This jihadist connection, however, should not make us overlook the fact that the environment of ethnic conflict in Asia also proves fertile ground for organized crime and draws on it as a major source of funds for armed struggles. The Abu Sayyaf group, for one, finances its activities primarily with the proceeds of kidnapping. Other groups in Burma, Bangladesh and northeast India are involved in the production and smuggling of drugs.

While similar types of escalation are under way in Africa and have already had a certain measure of success in the east (specifically Kenya, Tanzania and Uganda), the Horn (Eritrea, Ethiopia, Somalia) and Nigeria, the strategy of implanting Islamic jihad in any of Europe's ethnic conflicts has so far been relatively ineffective. Here, the major new dimension of spread is organized crime. In Kosovo, various groups have long been involved with drug smuggling, gunrunning and human trafficking. Kosovar Albanian mafia groups today control much of Western Europe's prostitution. And Transnistria in Moldova, an unrecognized separatist entity, is a major source and transport route for drugs, cigarettes and women destined for the sex industry in Europe.

THE GENERAL point here is not to criminalize what are often legitimate grievances of suppressed population groups, but to highlight that ethnic conflict spreads in very different ways. Even in an age when international terrorism is seen as the greatest scourge, ethnic conflicts-no matter how far away they happen-pose serious security challenges and need to be tackled.

For the most part, ethnic conflicts are political conflicts. They can be resolved in a bargaining process in which all parties can agree on institutions, rules and regulations that allow them to resolve their disagreements by political rather than violent means. Sensible policy responses need to take account of the causes and consequences of traditional and nontraditional patterns of diffusion and escalation if they want to succeed.

Removing the motive for people to spread ethnic conflict would be the most likely strategy of sustainable success. This would mean addressing greed, grievance and security concerns of ethnic communities, states and private-interest groups. Obviously, this is easier said than done, not least because it is often rather difficult, if not outright impossible, to disentangle the various actors' claims, especially if they have become interwoven over long periods of time. Removing motivations is more likely to be possible in cases where criminal and international terrorist involvement is minimal. Here, policy responses must start by taking the concerns of all actors involved seriously and striving for comprehensive bargains using pressures and incentives alike to make solutions sustainable. It also means using the traditional mechanisms to prevent spread: eliminating potential spoilers, stopping flows of arms, money and "expertise" to susceptible areas, and diaspora support.

Not creating the kind of opportunity in which developments in one ethnic conflict can, beyond all proportions, have global ramifications is primarily a responsibility of political leaders. Rather than letting themselves be driven by short-term domestic concerns (presidential elections in Cyprus, parliamentary elections in Spain, a weak presidency in Romania, etc.), political leaders need to show skill, vision and responsibility when dealing with matters of ethnic conflict and its diffusion and escalation.

Settling ethnic conflicts before they can spread and preventing them before they happen would of course be the most sensible strategy of all. Yet, we have to be realistic about the extent to which this is possible now and in the future. Effective policies prioritize political solutions but are willing to draw on a wide range of other options, including military and judicial ones, to deal with the unholy trinity of ethnic conflict, organized crime and international terrorism. This is the best way to remove the motivations, seize the means and eliminate the opportunities to allow ethnic conflict to spread. Taking this approach will not resolve all ethnic conflicts or prevent the emergence of new ones, but it will put an effective stop to the spread of existing ones.

Stefan Wolff is a professor of political science and the director of the Centre for International Crisis Management and Conflict Resolution at the University of Nottingham in England. He is also the author of Ethnic Conflict: A Global Perspective (Oxford University Press, 2006).