One of the big problems with people such as yourself as well as most journalists is that you are hopelessly uneducated.
Educated people know that the U.S. has nuclear-armed Trident submarines which can not be detected by the rest of the world. It's safe to say that they would always be able to get off a shot. Educated people know that the U.S. maintains secure ICBM's in thousands of diverse locations. Timing and geography insure that we will always be able to get most of those shots off regardless of the form of attack against us.
Further, educated people know that North Korea, Iran, Iraq, and Syria have never carried out a single nuclear test (which are easily detected with century-old seismic equipment). You don't go starting a nuclear war with the U.S. if you aren't certain that your nukes work in the first place.
Moreover, Russia is on our side and China DESPISES the Islamic militants who are causing trouble in its Western provinces. In fact, Russia is literally at war with Muslims in Chechnya, Bosnia, and Serbia/Kosovo. Furthermore Russia really wants to sell its oil to the largest oil consumer on the planet, the U.S. (not that you'd know that fact, either). Clearly their economy would suffer if the largest market in the world were to be suddenly nuked.
What is even more clear is that you are a typical uneducated newbie who spouts nonsense on FR. Come back when you get a real education. Until then, go away.