Does California deserve to have its own independent government as well as a seat in the United Nations?
Given the facts that the state of California is a major world power, and it has the 10th largest economy in the world, a population greater than Canada, a fully developed infrastructure, and its own distinct culture, do you think California could be a separate nation?
I think you'll find that the 14th Amendment to the US Constitution pretty much prohibits this. Secession from the union of the United States of America was an open question legally before the Civil War, or War of Secession as it is still often referred to in the South (incidentally a more accurate term, since a "civil war" implies two sides struggling for control of a central government, which was not the case). The 1830 Senate debate between Robert Hayne and Daniel Webster centered on whether the Constitution was a treaty between the several states or the founding of a single country. The issue was pretty much decided by the war and the amendment.
The 14th Amendment, among other things, defines exactly who and what is "citizen" and "citizenship" in the US, something lacking in the Constitution itself. For all practical purposes the discussion of secession in the US (frequently an issue in Vermont, for instance) is a moot point. The concept of the Constitution as a treaty between the states (and therefore the states as individual sovereign nations) is as dead as any political issue could be. There are legal arguments about secession of states or regions, or the concept of union with Canada, or the cession of a state or region to another sovereign nation, but none of these seems to have any real chance of occuring.
Internationally, there are two intriguing and simultaneous patterns emerging worldwide, one for an ever-more united world or at least ever larger international unions, and the other of ever-smaller regional and ethnic groups attempting to have their own nations. It's going to be fascinating to see where this all leads in the future, although I personally can't see it having any other effect than more wars.
Certainly, California has some formidable statistics which would rival other nations' status. However, the undeniable element is that California is part of the United States, and if the precedent is set that one state is officially recognized as a nation, then it stands to reason that other states could be acknowledged as such. America experienced this in the days after the American Revolution, when the Articles of Confederation was merely "a loose association of states." This denied social unity, national cohesiveness, and every state looked out only for its own interests, and not that of the nation's. Some will argue that the history indicates that California was another nation's property, and its acquisition was achieved through war. While this is valid, the reality is that if precedent is set with California being recognized as its own state and a separate nation, the nation would be challenged to actually act and function as a "nation." Our history shows only dread when examining what happens when states view themselves as separate from a union, able to act independent of the other states in the union.