including any one of the fifty states.
The order to pay spousal support can be enforced in any state. The normal procedure is to register the decree in the paying spouse's state by filing certified copies with the local court. That court can then take the action necessary to collect the money like having the support withheld from pay and holding the delinquent party in contempt.
Payment can also be enforced in the state that granted the divorce. The court there can order wage-withholding and hold a delinquent party in contempt. But often it is more cost-effective to do the enforcement in the state where the paying spouse lives. It is easier to have a party held in contempt and sent to jail in the state where they live for the simple reason that the local sheriff can go to their house and arrest them. The sheriff from the state where the divorce was granted, on the other hand, cannot cross a state line to arrest someone who hasn't paid their support and extradition in these cases is rare.