Don't be naive. Our longstanding position is that we have a nuke doctrine that says "you hit us with nuke/chem/bio, and we nuke you."
They hit us with bio. If we don't nuke them, we're sending a clear message: it's safe to hit us, because we talk big, and we wave a mean stick, but when the day is done, we'll take it, because we're a paper tiger.
As to your notion that they're playing by some tit for tat rules, get real. We're the ones playing this with the Marquis of Queensbury in one hand an Roberts Rules of Order in the other. They do what they can get away with, and what will inflict the most harm to us.
Don't believe me? Then think back a few weeks. There used to be two big skyscrapers on the south tip of Manhattan. Now there ain't. Oops, there went your "don't hit them, or you'll give them an excuse to hit back" idea.
You are evidently one of those people who's never had to deal with a real bully. Or perhaps you dealt with a mini-snot of a bully, and you sucked it up, and he didn't take your lunch money, so now you think the whole world works like that.
Well, it doesn't. There are some real nasty mothers out there, and OBL is about as nasty as they come. Animals like that understand two things. The first if force. Overwhelming force. And the other is weakness. To them, it's a black and white world -- and as long as we're not giving them overwhelming force, in their eyes, we're weak.
<>"Our policy should be simple. Any nuke detonated on home soil and the rest of the world is going to see an extinction level event response from the USA. We have the subs, they should have their orders. America is nuked, end of days. It has to be said otherwise we may suffer the unimaginable."
Nice big-talk, but how would you avoid hurting the Innocent Civilians(tm)? Ahh, so much for that idea.
We can't even bomb the bastards on their so-called holiday, and you think we're gonna waste 'em to the ground? The weak among us would piss and moan about how "those children didn't set up us the bomb, how can you kill them?"
If we don't drop at least one token tactical nuke on the bastards, we're as much as telling them they've got carte blanche to do us up one side and down the middle. And they will. But as far as nuking them into oblivion? You're in fantasy land.