Fear is a major proponent of the mutual, self-perpetuating distrust between nuclear weapon states. Their insecurity promotes the construction of "worst-case scenarios" wherein each nation imagines the enemy's most ingenious and devastating schemes and then prepares to be capable of retaliating with enough severity to deter anyone from ever putting such plans into action. Because the process is reciprocal, it risks turning the arms race into a mutually self-fulfilling prophecy. Adversaries which view one another as warlike and treacherous find their belief verified by the response each other makes in the face of such threats. Each notes the other's military build-up, aggressive propaganda, efforts at subversion, massive arms sales and donations abroad, and its violations of international law.
Insecurity among nations undermines joint action to reduce the risks of nuclear catastrophe at every step. Keeping pace with the escalating powers of destruction, distrust also spurs them on, while blocking all moves to curb them. Out of a degree of insecurity and distrust that once would have seemed pathological, the nuclear weapon states now compete with one another in perfecting the means to global catastrophe.