Could the union strike (after the bankruptcy proceedings are complete) and force the state to take on new debt? Can states (or municipalities) not declare bank

Could the union strike (after the bankruptcy proceedings are complete) and force the state to take on new debt? Can states (or municipalities) not declare bankruptcy, and instead default on only the obligations they don't want to pay? That would be similar to how I as an individual can just stop paying one credit card but not the other. Or are those left holding the bag able to sue and force bankruptcy proceedings?