I’m not sure if hypersonic missiles or Iran’s drones have a chance of first strike capability. If so, or if some countries will think so, and/or don’t fear a second strike, then we need to take preventative steps. The same applies to nuclear weapons (with or without these,) and perhaps likewise even poison gas.
If there is a chance of conquest by China, Iran, or North Korea — or a chance of destruction by any of those countries or by Russia, we need a freeze on new missiles and/or weapons of those sorts; there should be immediate inspection of any suspicious sites in order to verify this. (If they don’t fear a second strike, or would furnish to terrorists, we need to have them dismantle what they already have—again with immediate inspection.)
Perhaps the way to do this is by offering and/or establishing increased trade while threatening increased sanctions, with the spread wide enough so that they won’t want to chance our missing any of the sites.