 Prevention. Cases of preemption tend to be handled easily by process theories of causation, whereas counterfactual, manipulation, probabilistic, and regularity theories have more difficulty saying both that the preempting c is a cause of e and that the preempted backup b is not a cause of e. For, in cases of preemption, we can easily trace out the process whereby c leads to e, whereas the process which would have led from b to e was interrupted by c. On the other hand, process theories have more difficulty with cases of prevention. Here’s a case of prevention: over the Atlantic ocean, James Bond shoots down a missile which is heading for Blofield’s compound, and Blofield survives unscathed. Bond prevented Blofield from dying. If we understand prevention as causation-not (c prevents e iff c caused it to be the case that e didn’t happen), then Bond caused Blofield to not die. But there does not appear to be any causal process leading from Bond to Blofield—both Bond and the missile were thousands of miles away.