One of the striking differences between the American Revolution and most modern independence movements is that the former was not based on ethnic or nationalistic justifications. Nowhere does the Declaration state that Americans have a right to independence because they are a distinct "people" or culture. They couldn't assert any such claim because the majority of the American population consisted of members of the same ethnic groups (English and Scots) as the majority of Britons.

Rather, the justification for American independence was the need to escape oppression by the British government - the "repeated injuries and usurpations" enumerated in the text - and to establish a government that would more fully protect the rights to "life, liberty, and the pursuit of happiness." The very same rationale for independence could just as easily have been used to justify secession by, say, the City of London, which was more heavily taxed and politically oppressed than the American colonies were. Indeed, the Declaration suggests that secession or revolution is justified "whenever any Form of Government becomes destructive of these ends" [emphasis added]. The implication is that the case for independence is entirely distinct from any nationalistic or ethnic considerations.

By contrast, modern international law, such as the International Covenant on Civil and Political Rights assigns a right of "self-determination" only to "peoples," usually understood to mean groups with a distinctive common culture and ethnicity. If the American Revolution was justified, the ICCPR's approach is probably wrong. At the very least, secession should also be considered permissible where undertaken to escape repression by the preexisting central government. For example, Taiwan's de facto secession from China in 1949 was surely justified, despite the fact that most of the island's population consists of ethnic Chinese.

The Chinese on Taiwan seceded for the purpose of escaping rule by a communist regime that went on to slaughter millions of its own people. Had it retained control of Taiwan, it would likely have oppressed its population far worse than anything 18th century Americans suffered at the hands of the British. Today's Chinese regime is much less brutal than that of Mao Zedong; but it is still much more repressive than Taiwan's own government. Athough the Taiwanese government continues to affirm that the island is officially a part of China, it is in reality a separate nation in everything but name. Formalizing Taiwan's independence might be pragmatically unwise for any number of reasons. But that in no way undermines the moral case for it.

The case for allowing non-ethnic secession in cases where it is used to escape brutal repression strikes me as overwhelming. More controversial is the case for allowing it in situations where a group seeks to secede merely because they believe they can establish a better government than the status quo, even if the latter is not unusually oppressive. In my view, this type of secession should also be permitted, so long as the secessionists do not plan to engage in oppression of their own, and meet a few other criteria. I will not, however, try to argue for this broader right to secession here; those interested in the relevant argument should check out Christopher Wellman's excellent book on the subject. For now, I will only suggest that the example of the American Revolution and other similar situations provides a strong argument for allowing non-ethnic secession in cases where it is used to escape a repressive central government.