US nuclear warheads have undergone a radical shift in capability which according to this paper actually make the Russian Paranoia more understandable. We have optimized the US for a first strike. The last quote in the paper by Putin is chilling. Fearful times when paranoia and thin skinned inexperience hands are hovering over the nuclear buttons
http://thebulletin.org/how-us-nuclear-force-modernization-undermining-strategic-stability-burst-height-compensating-super10578