Secessionist Movements

Ripstein, when discussing Kant's argument, notes that "The 'legalistic' argument said that there was no juridicial mechanism through which the people could reserve to itself the right of sedition or rebellion; this further argument says that there is no people except as represented by law." (336). This is founded on the idea that the only legitimate way to exercise force is through an expression of the omnilateral will. In most cases, revolutionaries are incapable of meeting that basic justification. Nevertheless, in the case of secession, the dominant issue that emerges is what to do when there are conflicting omnilateral wills. 

Quickly, the secessionist movement I write of would have to have the following qualities: a legitimate government (think a US state) to express the omnilateral will of that polity and the grounds of the secessionist movement is inherently public (in the sense that its leaders are not seceding for private gain).  

By using the omnilateral will to secede from the government, secessionist movements raise an interesting issue. On one level, it would be easy to dismiss the claims or actions of the secessionist government as essentially a unilateral will within a broader polity. This makes some sense, given that the secessionist government, by definition, would not comply with the broader government. But this is strange in two ways. First, it means that we are to only pick the "largest" will, which seems morally arbitrary. Second, if these movements come from within what everyone regards as a legitimate government, we must take those actions themselves as being legitimate. Perhaps, at some level then, Kant and Ripstein have to take into account these movements, if only for a clearer enunciation of in what situations the omnilateral will itself is legitimate. Does anyone have any thoughts on how to resolve this conflict?