Decades, maybe centuries.
Locked in eternal struggle in a place between time and space...no wait, that was somebody else.
Bowser has the virtue of being perfectly consistent--he didn't think we should have attacked Afghanistan, either. I suspect, but don't know, that he had an unpleasant experience in the military.
That, and like me, he gets some amusement now and then from pulling chains. Although I'm cutting back for my health...