Do you really want to risk Russian retaliation on behalf of Norway? That's the outcome of our decades old treaty with Norway.
Once India is included in America's nuclear umbrella, a Chinese nuclear attack against India becomes a non-option for the Chinese. The disarmament of India then allows the roll back of the world's first "Islamic Bomb" which could very easily become the world's first "Islamist Bomb".
As for missile defense, I will quote my former Commanding Officer of a CGN (nuclear powered guided missile cruiser), "The best protection our Battle Group has is the elimination of the enemy by our carrier aircraft before they ever become a threat to us. Once we (our CGN) come into play and we are forced to try to shoot down the Bad Guy's bullets, we're in deep sh*t."