What Next?

Perhaps the most tragic example of the problems created by large refugee flows occurred in the wake of the Rwandan genocide in 1994. After the Hutu-led genocide resulted in the death of 800,000 to 1 million Tutsis and moderate Hutus, the Tutsi-led Rwandan Patriotic Front "invaded" the country from neighboring Uganda. The RPF was drawn from the 500,000 or so Tutsis who had already fled Rwanda from past pogroms. As the RPF swept through Rwanda, almost 1 million Hutus fled to neighboring Congo, fearing that the evil they did unto others would be done unto them.

For two years after 1994, Hutu bands continued to conduct raids in Rwanda and began to work with Congolese dictator Mobutu Sese Seko. The new RPF government of Rwanda responded by attacking not only the Hutu militia camps, but also its much larger neighbor, bolstering a formerly obscure Congolese opposition leader named Laurent Kabila and installing him in power in Kinshasa. A civil war in Congo ensued, killing perhaps 4 million people.

The flow of refugees from Iraq could worsen instability in all of its neighboring countries. Kuwait, for example, has just over 1 million citizens, one-third of whom are Shiite. The influx of several hundred thousand Iraqi Shiites across the border could change the religious balance in the country overnight. Both these Iraqi refugees and the Kuwaiti Shiites could turn against the Sunni-dominated Kuwaiti government, seeing violence as a means to end the centuries of discrimination they have faced at the hands of Kuwait's Sunnis.

Numbers of displaced people are already rising in Iraq, although they are nowhere near what they could be if the country slid into a full civil war. About 100,000 Arabs are believed to have fled northern Iraq under pressure from Kurdish militias. As many as 200,000 Sunni Arabs reportedly have been displaced by the fighting between Sunni groups and the American-led coalition in western Iraq. In the past 18 months, 50,000 to 100,000 Shiites have fled mixed-population cities in central Iraq for greater safety farther south. So far, in addition to the Palestinians and other foreigners, only the Iraqi upper and middle classes are fleeing the country altogether, moving to Egypt, Jordan, Lebanon or the Gulf States. As one indicator of the size of this flight, since 2004 the Ministry of Education has issued nearly 40,000 letters permitting parents to take their children's academic records abroad. If the violence continues to escalate, even those without resources will soon flee to vast refugee camps in the nearest country.

Terrorism Finds New Homes

The war in Iraq has proved to be a disaster for the struggle against Osama bin Laden. Fighters there are receiving training, building networks and becoming further radicalized -- and the U.S. occupation is proving a dream recruiting tool for young Muslims worldwide. As bad as this is, a wide-scale civil war in Iraq could make the terrorism problem even worse.

Such terrorist organizations as Hezbollah, the Liberation Tigers of Tamil Eelam (LTTE), the Armed Islamic Group (GIA), the Irish Republican Army (IRA) and the Palestine Liberation Organization (PLO) were all born of civil wars. They eventually shifted from assaulting their enemies in Lebanon, Sri Lanka, Algeria, Northern Ireland and Israel, respectively, to mounting attacks elsewhere. Hezbollah has attacked Israeli, American and European targets on four continents. The LTTE assassinated former Indian prime minister Rajiv Gandhi because of his intervention in Sri Lanka. The IRA began a campaign of attacks in Britain in the 1980s. The GIA did the same to France the mid-1990s, hijacking an Air France flight then moving on to bombings in the country. In the 1970s, various Palestinian groups began launching terrorist attacks against Israelis wherever they could find them -- including at the Munich Olympics and airports in Athens and Rome -- and then attacked Western civilians whose governments supported Israel.

In Afghanistan, the anti-Soviet struggle in the 1980s was a key incubator for bin Laden's movement. Many young mujaheddin went to Afghanistan with only the foggiest notion of jihad. But during the fighting in Afghanistan, individuals took on one another's grievances, so that Saudi jihadists learned to hate the Egyptian government and Chechens learned to hate Israel. Meanwhile, al-Qaeda convinced many of them that the United States was at the center of the Muslim world's problems -- a view that almost no Sunni terrorist group had previously embraced. Other civil wars in Muslim countries, including the Balkans, Chechnya and Kashmir, began for local reasons but became enmeshed in the broader jihadist movement. Should Iraq descend into a deeper civil war, the country could become a sanctuary for both Shiite and Sunni terrorists, possibly even exceeding the problems of Lebanon in the 1980s or Afghanistan under the Taliban.

Right now, the U.S. military presence keeps a lid on the jihadist effort. There are no enormous training camps such as those the radicals enjoyed in Afghanistan. Likewise, Hezbollah and other Shiite terrorist groups have maintained a low profile in Iraq so far, but the more embattled the Shiites feel, the better the chance they will invite greater Hezbollah involvement. Shiite fighters may even strike the Sunni backers of their Iraqi adversaries, such as Saudi Arabia and Kuwait, or incite their own Shiite populations against them. And lost in the focus on Arab terrorist groups is the Kurdish Workers Party (PKK), an anti-Turkish group that has long fought to establish a Kurdish state in Turkey from bases in Iraq. The more Iraq is consumed by chaos, the more likely it is that the PKK will regain a haven in northern Iraq.

The Sunni jihadists would be particularly likely to go after Saudi Arabia given its long, lightly patrolled border with Iraq, as well as their interest in destabilizing the ruling Saud family. The turmoil in Iraq has energized young Saudi Islamists. In the future, the balance may shift from Saudis helping Iraqi fighters against the Americans to Iraqi fighters helping Saudi jihadists against the Saudi government, with Saudi oil infrastructure an obvious target.

Radicalism Is Contagious

Civil wars tend to inflame the passions of neighboring populations. This is often just a matter of proximity: Chaos and slaughter five miles down the road has a much greater emotional impact than a massacre 5,000 miles away. The problem worsens whenever ethnic or religious groupings also spill across borders. Frequently, people demand that their government intervene on behalf of their compatriots embroiled in the civil war. Alternatively, they may aid their co-religionists or co-ethnics on their own -- taking in refugees, funneling money and guns, providing sanctuary.

The Albanian government came under heavy pressure from its people to support the Kosovar Albanians who were fighting for independence from the Serbs. As a result, Tirana provided diplomatic support and covert aid to the Kosovo Liberation Army in 1998-99, and threatened to intervene to prevent Serbia from crushing the Kosovars. Similarly, numerous Irish and Irish American groups clandestinely supported the Irish Republican Army, providing money and guns to the group and lobbying Dublin and Washington.

Sometimes, radicalization works in the opposite direction if neighboring populations share the grievances of their comrades across the border, and as a result are inspired to fight in pursuit of similar goals in their own country. Although Sunni Syrians had chafed under the minority Alawite dictatorship since the 1960s, members of the Muslim Brotherhood (the leading Sunni Arab opposition group) were spurred to action when they saw Lebanese Sunni Arabs fighting to wrest a share of political power from the minority Maronite-dominated government in Beirut. This spurred their own decision to organize against Hafez al-Assad's regime in Damascus. By the late 1970s, their resistance had blossomed into civil war, but Assad's regime was not as weak as Lebanon's. In 1982, Assad razed the center of the city of Hama, a Muslim Brotherhood stronghold, killing 20,000 to 40,000 people and snuffing out the revolt.