The real danger to our planet comes not from a sudden technological breakthrough which would make nuclear war safe, but from the demented filled minds of the US Neocons who believe that they can bring Russia to heel in a game of "nuclear chicken". These Neocons have apparently convinced themselves that making conventional threats against Russia, such as unilaterally imposing no-fly zones over Syria, does not bring us closer to a nuclear confrontation. It does.
The Neocons love to bash the United Nations in general, and the veto power of the Permanent Five (P5) at the UN Security Council, but they apparently forgot the reason why this veto power was created in the first place: to outlaw any action which could trigger a nuclear war. Of course, this assumes that the P5 all care about international law. Now that the USA has clearly become a rogue state whose contempt for international law is total, there is no legal mechanism left to stop the US from committing actions which endanger the future of mankind. This is what is really scary, not "super-fuses".
What we are facing today is a nuclear rogue state run by demented individuals who, steeped in a culture of racial superiority, total impunity and imperial hubris, are constantly trying to bring us closer to a nuclear war. These people are not constrained by anything, not morals, not international law, not even common sense or basic logic. In truth, we are dealing with a messianic cult every bit as insane as the one of Jim Jones or Adolf Hitler and like all self-worshiping crazies they profoundly believe in their invulnerability.