The BBC reports on a debate held in Philadelphia between American lawyers and British barristers. (source)
The American side of the debate:
The Declaration is unquestionably “legal”. Under basic principles of “Natural Law”, government can only be by the consent of the people and there comes a point when allegiance is no longer required in face of tyranny.
The legality of the Declaration and its validity is proven by subsequent independence movements which have been enforced by world opinion as right and just, based on the fundamental principles of equality and self-determination now reflected in the UN Charter.(source)
And the British:
The Declaration of Independence was not only illegal, but actually treasonable. There is no legal principle then or now to allow a group of citizens to establish their own laws because they want to. What if Texas decided today it wanted to secede from the Union?
Lincoln made the case against secession and he was right. The Declaration of Independence itself, in the absence of any recognised legal basis, had to appeal to “natural law”, an undefined concept, and to “self-evident truths”, that is to say truths for which no evidence could be provided.
The grievances listed in the Declaration were too trivial to justify secession. The main one – no taxation without representation – was no more than a wish on the part of the colonists, to avoid paying for the expense of protecting them against the French during seven years of arduous war and conflict. (source)
Naturally, I side with the American view. However, it seems that both sides’ arguments are awfully hypocritical. To argue that the government can only be by the consent of the people, and that independence movements are just and right flies in the face of the fact that more Americans died trying to prevent an independence movement than in all other U.S. wars combined. Independence and its lofty rhetoric didn’t do much for the south when it decided that it no longer consented to rule from Washington. Apparently the view is that Independence was legal once, but from that point forward, never again.
On the other hand, for anyone in the United Kingdom to argue about the illegality of secession turns my stomach. I would like to see the same barristers explain how it is illegal to seek to leave an empire, but somehow legal to subjugate Ireland, India, South Africa, and so on. Is the position the Crown may take, but what the Crown takes, it must never give up until it is damn good and ready?