 By analogy with ordinary preemption, we can call the first case an instance of early preemptive prevention. Once Bond tells M that he will shoot down the missile, M is no longer a potential preventer of the missile strike. If, at the last minute, Bond had changed his mind, Blofield’s compound would have been destroyed. In contrast, we can call the second case an instance of late preemptive prevention. At no point does the missile defense system “step down”, and stop being a potential preventer of the compound’s destruction.