A warning for those who think the UK will always be able to leave the EU

From Wikipedia

"Secession
The Constitution is silent on the issue of the secession of a state from the union. The Articles of Confederation had stated that the earlier union of the colonies "shall be perpetual", and the preamble to the Constitution states that Constitution was intended to "form a more perfect union". In 1860 and 1861, several states attempted to secede, but were brought back into the Union by force of arms during the Civil War. Subsequently, the federal judicial system, in the case of Texas v. White, established that states do not have the right to secede without the consent of the other states."

That's secession from the USA, do you think that the EU will make it any easier fort states to leave the EU?