This is a wrong question to ask, because it presupposes a certain concept of state. Specifically, it anthropomorphizes the state, treating it as if it were an individual human being. Only then the question about "central objective: makes sense. However, if we recognize that states are complex entities composed of various groups pursuing different agenda, the question should be asked central for whom?"
It is quite common that single individuals do not pursue a single objective but multiple ones. If that is true of an individual, it is even more true of the state. Different power brokers might have very different goals in supporting the war. If I remember correctly, Wolfowitz was quite open about it, adding that they agreed on one official story for public consumption.
Wojtek