I haven't thought much about this, to be honest, but I want to argue the opposite. When considering the risks of nuclear war, there are (I would say) three pri

I haven't thought much about this, to be honest, but I want to argue the opposite. When considering the risks of nuclear war, there are (I would say) three principle risks: 1. An intentional first strike by an actor who is non-rational. (E.g., a believer in an apocalyptic ideology who does not respond to traditional deterrence.) 2. An intentional first strike by an actor who believes they can reduce or eliminate their target's second-strike capability (or for whom a nuclear first strike is otherwise a rational response). 3. An accidental launch due to C&C failures. (E.g., https://en.wikipedia.org/wiki/1983_Soviet_nuclear_false_alarm_incident. https://en.wikipedia.org/wiki/1983_Soviet_nuclear_false_alar...) I think one can easily argue that two of the three are more likely since the end of the Cold War! Risk #1 is rather obvious: the rise of international terrorism combined with an increase in the number of (domestically) weak state actors who have nuclear capabilities--post-Soviet Russia, Pakistan--makes the risk of nuclear attack (via stolen weapons) by non-state actors credible. Risk #2 is the one people normally think of, and, on a large scale--between traditional nuclear powers--it is probably lower than during the Cold War. I would consider two points here, however: first, this might never have been the principle risk during the Cold War (insofar as, with rational actors and full information, deterrence is effective), and second, there are multiple regional powers (again, the usual suspects: North Korea, Pakistan and India) for whom a first strike might be somewhat more tempting. Risk #3 is also arguably worse. While the total size of deployed unclear arsenals has declined, the number of nuclear states has increased, increasing the odds on a C&C failure for any given nuclear state. Interestingly, the significant point among all three observations boils down to "nuclear arms proliferation", which, well, duh--that increases the opportunity for mistaken or miscalculated use of nuclear weapons. More interestingly, the US considering a withdrawal from the Open Skies Treaty goes to another point: information access. As I noted above, deterrence seems to work with rational actors who have perfect information--by reducing access to information, we increase risks.