Right, but I thought Littlefinger started the madness by claiming kidnapping to get Robert and the Starks to behave in exactly the way he expected them to, to make sure they were killed off and he'd get Catelyn. The chaos causing the Targaryens to be driven out and a weaker Robert put in place with Littlefinger gaining more and more influence were side bonuses.
I don't think that has ever been stated.
Did Littlefinger even have any role in that war? I don't really recall much talk of his involvement in Robert's Rebellion.