Parma is not truly a state of its own, but a region of the Victarian Empire. Nonetheless, they are subservient only in theory. The truth is, the bulk of Parma’s wealth comes from black market trade, and the "state" has little interest in the wars and political squabbling between the other Confederate nations. All its leaders want is to steal and facilitate trade—both legal and illegal.
But while Parmanians do not openly resist the Confederate world order, they also have no qualms about raiding Victarian and Treemean convoys, ships, and facilities whenever the act cannot be tied back to Parma. Regardless of their perceived cunning, Victaria is well aware of their ally's treasonous nature, and allows such activity to continue only so it can keep its focus lanced on the war effort in the East.