If a nation have a H-Bomb, it is considered to be invincible. That's the key point behind going for it.

I suppose that there is NO practical use of having a H-Bomb. There is lots of effort needed to keep it safe. I mean to say, Big nations assume that they are the only responsible nations and this is their sole responsibilty to keep this world safe. There is always a sense of apprehension if terrorists got control to these bombs they can use it against the humanity.

US sees itself as terrorist's favorite target.