I am wondering If Arizona has the same treaty as does the Dakotas and Wyoming where they can leave the union under specific circumstances?
I don't know. They might. Lots of western states have special provisions that had to be in there for them to agree to becomes states.
Doesn't the state also have the same obligation to uphold the sovereignty of the country, even through force?
Not really. We're technically a federation, which means the sovereignty of the state (is supposed be) superior to the sovereignty of the national government. The waters were first muddied when the first federal income tax was put in place, first temporarily during the Civil War, and then permanently with the 16th Amendment, and then things got decidedly murkier when the 17th Amendment took away the state's control (or at least an avenue of partial control) over the federal government via the representation of each state's legislature in the US Senate. Not only did this throw the checks and balances of the federal government by the states out the window, it gave the feds far too much control over the states, since special interests, which had had great difficultly influencing the system when state legislatures controlled the Senate, now can appeal directly to the electorate regardless of what the State Legislatures want.
The states are really under no obligation to enforce federal sovereignty, but the federal government is supposed to enforce state sovereignty. Under Chief Justice William Rehnquist, the Court slowly, but steadily, began cutting back federal powers and protecting state's rights. But some of that has swung back the other way since 911.
However, the Tenth Amendment is what matters most, even though it's only been applied by the Supreme Court twice, so far. It's an Amendment that is under attack, and is being even more strongly defended at the moment, with things like the REAL ID Act, the abuses of the Commerce Clause and mandatory health care, Firearm Freedom Act, where states have passed blatant nullification legislation to protect themselves.
The powers not delegated to the United States by the Constitution, nor prohibited by it to the States, are reserved to the States respectively, or to the people.
This prevents the federal government from mandating forced participation or commandeering, or from forcing the states to become an instrument of the federal government (to implement or enforce federal laws and programs). Of course, the federal government can hijack federal funds in exchange for cooperation, something knows as
cooperative federalism. Case in point is when Congress passed the National Minimum Drinking Age Act which made the national drinking age 21. The federal government withheld 10% of the Federal-Aid Highway Act funds from states which did not knuckle under. South Dakota promptly sued Elizabeth Dole personally, which still cracks me up, because she was the Secretary of Transportation, the office which enforces the law. South Dakota argued that the establishment of a minimum drinking age of 21 wasn't sufficiently related to that of Interstate highway construction so as to justify conditioning funds appropriated for that purpose. Two justices agreed, seven of 'em didn't, stating that the conditions were merely "pressure" and not "compulsion."
So States really aren't obligated to enforce or protect federal sovereignty other than to the point where they are protecting themselves.
