The roots of the current Russo-Georgian crisis are complex. Geopolitically, the Russian invasion of Georgia represents Moscow's attempt to reassert its dominance in the Caucasus and Central Asia while sending a message that Russia is now strong enough to counter Western incursions into its sphere of influence.
But in so doing, the Russians are also exploiting a dangerous and frequent source of conflict in the international arena: the clash between sovereignty and self-determination.
In this case, it's the sovereignty of Georgia, an independent state recognized by the international community, that's in conflict with the self-determination of the South Ossetians.
They are a disaffected minority within Georgia who wish to secede and unite with North Ossetia, which is under Russia's political control. Russia has recognized South Ossetia's "independence," exploiting the attempted secession to punish Georgia for its defiance of Russian power and to deny Georgia's attempt to align itself with the liberal West.
The modern state, for all its shortcomings, has been a source of stability in the international system. Unfortunately for international peace and security, state boundaries often include populations that do not wish to be part of a given state.
Such populations are motivated by the principle of ethnic or national self-determination, a principle associated with nationalism, the belief in a common identity based on blood or language.
Modern nationalism is based on the idea that mankind is naturally divided into nations and that there are determinate criteria for identifying a nation and recognizing its members. Nationalism holds that each nation is entitled to an independent government of its own and that states are legitimate only if constituted in accordance with this principle.
Peace will prevail only when every nation forms a single state and every state consists exclusively of the whole of one nation. As the 19th-century Italian nationalist Giuseppe Mazzini put it, the political unity and independence of every nation within the boundaries of its own state is ordained by God.
Such conditions rarely prevail. Accordingly, much of the conflict in the world since the breakup of the Soviet empire has been nationalist and ethnic in character.
Because nationalists are often highly suspicious, resentful, and fearful of other national groups (xenophobia), their movement frequently results in tension and bloodshed.
Such characteristics lay at the heart of the conflict that erupted in the Balkans and help to explain the genesis of the dispute between Georgia and South Ossetia that led to last month's Russo-Georgian war.
When Georgia declared its independence in 1991, the international community recognized its legal status. However, the international community did not extend statehood to Abkhazia and South Ossetia when those regions attempted to secede from Georgia.
There is a good reason for this. Allowing a disaffected minority to secede from a multi-ethnic state destabilizes an international system that is already under stress. Once the principle of secession is accepted as a legitimate remedy, where does it end? In chaos. Secession leads to further secession, to the proliferation of small, weak states that are prey to their stronger neighbors.
The tension between sovereignty and self-determination can also be seen as a clash between stability and justice.
This polarity has always posed a dilemma for the United States. On the one hand, Americans have often provided support for oppressed peoples throughout the globe. The Bush doctrine is far from an innovation when it comes to articulating the American mission in support of "ending tyranny in the world." Americans have always understood that the boundaries of states are often brutally arbitrary, paving the way for tyrannical states to oppress their citizens.
On the other hand, American statesmen have recognized that the logic of secession leads to unending conflict. And precedents matter. Many observers believe that Russian support for Ossetian independence is payback for US support of Kosovo's declaration of independence from Serbia in February.
Although the issue of secession for the US was settled militarily by the Union victory in the Civil War and settled legally by the 1868 Supreme Court decision, Texas v. White, the US might someday have to contend with the demand by a politicized Hispanic minority in the US Southwest for autonomy or even independence.
The tension between justice and security in the international system is not likely to abate in the foreseeable future. The only remedy for the inevitable conflicts arising from this tension is the spread of liberal principles, especially the principle of government of, by, and for, the people.
• Mackubin Thomas Owens is a professor of national security studies at the Naval War College in Newport, R.I., and editor of "Orbis," the quarterly journal of the Foreign Policy Research Institute in Philadelphia.