Consequently, the world will be less stable. The risk of intentional launch is negligible. There are no irrational rogues in world politics. Hypothetical ones would just as well find ways to poison urban water supply or let loose deadly biological organisms. The marginal risk of a state using WMD in a crisis situation can be better minimised by multilateral arms control.
Accidental launches are a more serious risk.
Some believe that nuclear weapons can never be disinvented. That is a matter of debate. But there is still a strong case for lowering the deterrence threshold. Some effort to explore the scope for Collective Missile Control as part of a multilateral arms control regime needs to be undertaken. Neither the threat perception underlying missile defence nor its practical potential is credible or realistic.