Why did you fail to mention that Virginia, New York, and Rhode Island specifically reserved the right to withdraw from the compact? (secede) And I think Texas may have done the same. In contracts, and I am sure that you know this, if a set of parties to the contract accepts a new party to the contract with qualifications set by the incoming new party, in this case the states I mentioned, then they accept the qualifications.
It follows then, that, at least in Virginia's case, the United States was guilty of invading a sovereign nation.