Deontic conditionals, whether those of ordinary discourse or the simplified versions invented by intensional logicians, are ethically neutral. You can apply them to state any ethical doctrine you please. The results will be only as acceptable as the doctrines that went into them.

Radical utilitarianism, stark and unqualified, is not a commonsensical view. Agreement with our ordinary ethical thought is not its strong point. It is no easy thing to accept the strange doctrine that nothing at all matters to what ought to be the case except the total balance of good and evil – that any sort or amount of evil can be neutralized, as if it had never been, by enough countervailing good – and that the balancing evil and good may be entirely unrelated, as when the harm I do to you is cancelled out by the kindness of one Martian to another.

Accept this strange doctrine, and what should follow? Exactly the strange consequences that McMichael complains of! Never mind the semantics of deontic conditionals. If you really think that only the total matters, then surely you ought also to think that little is obligatory (there are always alternative ways to reach a high total) and that much is permissible (no evil is so bad that it cannot be neutralized). It is not in the radical utilitarian spirit to believe in outright ethical requirements or prohibitions.

Order the worlds on radically utilitarian principles; then apply the semantics for deontic conditionals that I gave in Counterfactuals; and the results are as McMichael says they are.