-As I explained in my thread about philosophies, I am a utilitarian at heart, as such believing in an ends-based morality, and an Aristotelian, believing that said end should be human happiness. As such, I tend to believe that Freedom is not an end or a thing that is good in and of itself, but rather certain liberal-democratic policies (freedom of thought and plurality of political opinion in governance, leaving aside the matter of property which is where i break harshly with the libertarian set) have proven to enhance human wellbeing and happiness, and to that end they are good things
But there is a time and a place for everything. From a perspective of human welfare, American independence is neither here nor there; as Canada demonstrated that home-rule was only 90 years away, and America under the colonies was really not all that badly off (the British treated us much better than the Spanish did to their American colonies, or subjects of Imperial Russia, for instance), although American independence did allow for radical experiments in the matter of rapid expansion of the franchise and in modern government free of monarchy, so ultimately American independence did good things for the world and was a worthwhile endeavor (aside from enabling the expansion of the slave trade 30 years longer than if we had stayed under British rule)
To that end, secession is only worthwhile when the people that could take power are going to be better than the people who have power. Secession in America is synonymous with lost-cause Dixie conservatism, and secessionists look back to 19th century views on women, property, the environment, and religious freedom, thereby meaning that they should not be allowed out lest they enact these things. Similarly, Algeria does not deserve democracy while the "Democratic" opposition are the same guys who are currently being chased around Mali by the French for being a horde of terrorists.
Palestine's neither hear nor there, depending on how much of what Hamas says is just posturing and how much they really do just want to kill Jews (rather than have freedom or their fair share of political power vis-a-vis Fatah).
Chechnya, having been co-opted by the vicious Caucasus Emirate, does not deserve self-determination.
Although I also believe that larger countries are more viable politically, better able to act on the international scene and better able to help their citizenry enrich themselves, so I tend to believe that countries shouldn't fall apart over small differences, and would likely oppose it if, say, Vermont wanted out, even though an independent Vermont would likely be a "better" country than America proper.