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, and perhaps 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, we need to have them dismantle such missiles and/or weapons they already have; again there should be 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.
(In the case of Russia, perhaps we might also take diplomatic steps such as inviting them to join NATO. In the case of North Korea, perhaps we might also give them a choice between denuclearizing the Korean peninsula or putting enough arms in South Korea and nearby to destroy them.)
Perhaps we can bring about human rights, such as freedom of religion, and perhaps we can get China to stop supporting North Korea if nothing else works with the latter.