Unless the United States and the new government of Iraq take dramatic action to reverse the current trends, the internecine conflict in Iraq could easily spiral into a full-scale civil war, threatening not only Iraq itself but also, even more vitally, its neighbors throughout the oil-rich Persian Gulf. Spillover from an Iraqi civil war could prove the greatest threat to peace in this strategically and economically crucial region. Spillover refers to the tendency of civil wars to impose burdens, create instability, and even trigger civil wars in other, usually neighboring, countries.
This tendency to inflame the passions of neighboring populations is, at the most basic level, simply a matter of proximity. It is far easier for people to identify and empathize with those they live near, even if they are on the other side of an imaginary boundary. Invariably, the problem is exacerbated whenever ethnic, religious, racial, or other groupings spill across those borders. The members of a group have a powerful tendency to take the side of, support, and even fight on behalf of the members of their group in the neighboring country. This sense of cross-border affinity, indeed kinship, is particularly strong in the Middle East.
Unfortunately, Iraq appears to have many of the conditions most conducive to this kind of spillover because of the high degree of foreign “interest” in the country. Ethnic, tribal, and religious groups within Iraq are prevalent in neighboring countries, and they share many of the same grievances. Iraq’s history of violence with its neighbors has fostered desires for vengeance and fomented constant clashes. Its neighbors also covet Iraqi resources, such as oil and important religious shrines. Commerce and communication between Iraq and its neighbors is high, and its borders are porous, which suggests that spillover from an Iraqi civil war would tend toward the more dangerous end of the spillover spectrum.