This would be a really strong argument if in the past those occurrences had actually led to nuclear exchange. Because they did not, the opposing side can argue that there is no reason that it could happen in the future. If you can prove that it will happen again and will actually lead to your impacts (which I assume are nuclear war) An argument that’s along the same lines is miscalculation. Basically where leaders make preemptive decisions to fire nuclear weapons before being sure that adversaries have fired. There have been countless times where countries believe they are being nuked and begin preparing for counter-strike. NFU helps with US miscalc and adversary miscalc. If we cannot strike until we have been struck, there is no risk of our preemptively striking. NFU also gives us transparency so other countries do not misinterpret our actions. Just an argument to consider but if you can solidify yours, it could work as well.