Use of the 'insanity' metaphor in reference to possible aggressive actions in Yemen is apt. I would suggest an elaboration: serial head banging against multiple walls. For that is what we have been doing in our eight year "war on terror."
We repeatedly run into walls head first when we invade and occupy countries (Afghanistan, Iraq); when we try to manipulate politics in place we understand poorly and that react negatively to our interference (Pakistan, Somalia, Palestine, Iraq, Afghanistan); when we broadcast that our objective is zero threat and absolute security; when we make believe that the rest of the world should or could see things the way we head bangers do.
We appear trapped in a room convinced that behind one of the walls lies the promised land -- if only we could find through dint of physical effort the right access point. This is multi-layered insanity. It is we ourselves who have created of tears. For one thing, we angrily keep stoking our collective fears. Witness the hysterical reaction to the underwear bomber. This inept try is the most serious in eight years. That should be occasion for relief and satisfaction, despite the demonstration of our equally inept security services. A second element is our tolerance for sloppy thinking and the policies that it engenders. The Afghan escalation is the latest case in point. Whatever one believes about the virtues of the course taken, the public arguments justifying it are full of holes. Obama's statements on the subject, frankly, are disdainful of public intelligence -- much less that of people like we. Third, the national discourse on terror has been irretrievably politicized in the worst sense of the term. Posturing and electoral considerations predominate. Candor is away with the leave of our leaders. Every public figure -- elected or unelected, national or local, Republican or Democrat -- jumps in as if it were 'garbage time' in a mid-season NBA game.